DocuSign SOAP API - Error: This Account lacks sufficient permissions

Question

I'm currently following the How-To Guide on how to Request a signature using SOAP API

I've imported the wsdl and managed to create my envelope but when I try to send it i face the following error : This Account lacks sufficient permissions. Without more context on why this error happens i found myself in a dead end.

From the how-to guide i replaced :
{USER_ID} by 1f8d\*\*\*\*-\*\*\*\*-\*\*\*\*-\*\*\*\*-\*\*\*\*\*\*\*\*7bcc found in Apps and Keys
{ACCOUNT_ID} by 2ba4\*\*\*\*-\*\*\*\*-\*\*\*\*-\*\*\*\*-\*\*\*\*\*\*\*\*2349 found in Apps and Keys
{USER_EMAIL} by a valid email of mine which i used with the rest API to make sure it worked just fine. This email is a different one than my account email.

Here is my request

POST /api/3.0/api.asmx HTTP/1.1
Host: demo.docusign.net
User-Agent: LibDocusign
Accept: */*
Accept-Encoding: deflate, gzip
Content-Type: text/xml; charset=utf-8
Connection: close
SOAPAction: "http://www.docusign.net/API/3.0/CreateAndSendEnvelope"
X-DocuSign-Authentication: My Docusign Integtation Key
Content-Length: 2326

<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
    xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <SOAP-ENV:Header>
        <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"
            xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" SOAP-ENV:mustUnderstand="1">
            <wsu:Timestamp wsu:Id="TS-102D96E1E732485F84CD0DCF095C5B08">
                <wsu:Created>2023-08-28T08:49:46Z</wsu:Created>
                <wsu:Expires>2023-08-28T08:50:46Z</wsu:Expires>
            </wsu:Timestamp>
            <wsse:UsernameToken wsu:Id="UsernameToken-0280BB10F71641FC8E680E1B93C1D8B0">
                <wsse:Username>My Developper User ID</wsse:Username>
                <wsse:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText">My Developper account Password</wsse:Password>
                <wsse:Nonce EncodingType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary">1WbYuC7dU8e6SaAqIwlUJw==</wsse:Nonce>
                <wsu:Created>2023-08-28T08:49:46Z</wsu:Created>
            </wsse:UsernameToken>
        </wsse:Security>
    </SOAP-ENV:Header>
    <SOAP-ENV:Body>
        <ns1:CreateAndSendEnvelope xmlns:ns1="http://www.docusign.net/API/3.0">
            <ns1:Envelope xmlns:ns1="http://www.docusign.net/API/3.0">
                <ns1:Recipients>
                    <ns1:Recipient>
                        <ns1:ID>1</ns1:ID>
                        <ns1:Email>me@mydomain.com</ns1:Email>
                        <ns1:UserName>Me</ns1:UserName>
                        <ns1:Type>Signer</ns1:Type>
                        <ns1:RequireIDLookup>false</ns1:RequireIDLookup>
                    </ns1:Recipient>
                </ns1:Recipients>
                <ns1:Documents>
                    <ns1:Document>
                        <ns1:ID>1</ns1:ID>
                        <ns1:Name>Lorem Document</ns1:Name>
                        <ns1:PDFBytes>QzpcVXNlcnNcTk9cRG9jdW1lbnRzXFZTQ29kZVRlbXBcRG9jdXNpZ25cZXhhbXBsZXNfYmFz&#13;
aFxkZW1vX2RvY3VtZW50c1xXb3JsZF9XaWRlX0NvcnBfbG9yZW0ucGRm</ns1:PDFBytes>
                    </ns1:Document>
                </ns1:Documents>
                <ns1:Tabs>
                    <ns1:Tab>
                        <ns1:DocumentID>1</ns1:DocumentID>
                        <ns1:RecipientID>1</ns1:RecipientID>
                        <ns1:Type>SignHere</ns1:Type>
                        <ns1:PageNumber>1</ns1:PageNumber>
                        <ns1:XPosition>100</ns1:XPosition>
                        <ns1:YPosition>100</ns1:YPosition>
                    </ns1:Tab>
                </ns1:Tabs>
                <ns1:AccountId>My Developper account ID</ns1:AccountId>
                <ns1:Subject>Test</ns1:Subject>
            </ns1:Envelope>
        </ns1:CreateAndSendEnvelope>
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

And the server response

HTTP/1.1 500 Internal Server Error
Cache-Control: private
Content-Type: text/xml; charset=utf-8
X-DocuSign-Node: DA1DFE5
Date: Mon, 28 Aug 2023 08:49:46 GMT
Content-Length: 1393
Connection: close
Strict-Transport-Security: max-age=31536000; includeSubDomains

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing"
    xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"
    xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">
    <soap:Header>
        <wsa:Action>http://schemas.xmlsoap.org/ws/2004/08/addressing/fault</wsa:Action>
        <wsa:MessageID>urn:uuid:4e384c84-1d55-46b4-ac47-3559fa6ab693</wsa:MessageID>
        <wsa:RelatesTo>urn:uuid:3c2851d0-6af1-4a5f-a213-539dd39b6aa7</wsa:RelatesTo>
        <wsa:To>http://schemas.xmlsoap.org/ws/2004/08/addressing/role/anonymous</wsa:To>
        <wsse:Security>
            <wsu:Timestamp wsu:Id="Timestamp-31d1e46c-c71d-4bf5-9bfd-3daa3ed9844d">
                <wsu:Created>2023-08-28T08:49:47Z</wsu:Created>
                <wsu:Expires>2023-08-28T08:54:47Z</wsu:Expires>
            </wsu:Timestamp>
        </wsse:Security>
    </soap:Header>
    <soap:Body>
        <soap:Fault>
            <faultcode>soap:Client</faultcode>
            <faultstring>This Account lacks sufficient permissions.</faultstring>
            <faultactor>missing in Web.Config</faultactor>
            <detail>
                <ErrorCode xmlns="missing in Web.Config">111</ErrorCode>
                <ErrorReason xmlns="missing in Web.Config">This Account lacks sufficient permissions.</ErrorReason>
            </detail>
        </soap:Fault>
    </soap:Body>
</soap:Envelope>

Any help would be appreciated. Thanks by advance