Why generating a PDF report creates an .HTML file?

Question

I am currently learning how to use Odoo. I am doing the following tutorial on PDF report generation.

The instruction is to allow the user to generate a pdf file gathering the offers that have been made for the purchase of a real estate property

It took me a long time to make the "Print" (on which clicking should generate a .pdf) button usable without getting an error telling me that wkhtmltopdf was not found on my computer.

It works now but I can't open the .pdf generated by Odoo.

Here is what I did on my side to get there

.xml files in Odoo

I work with version 16

I created a reports folder with two .xml files based on the examples in the tutorial

report_property_offers.xml

<?xml version="1.0" encoding="UTF-8" ?>
<odoo>
    <template id="report_property_offers">
        <t t-foreach="docs" t-as="property">
            <t t-call="web.html_container">
                <t t-call="web.external_layout">
                    <div class="page">
                        <h2>
                            <span t-field="property.name"/>
                        </h2>
                        <div>
                            <strong>Expected Price: </strong>
                            <span t-field="property.expected_price"/>
                        </div>
                        <table class="table">
                            <thead>
                                <tr>
                                    <th>Price</th>
                                </tr>
                            </thead>
                            <tbody>
                                <t t-set="offers" t-value="property.mapped('offers_ids')"/>
                                <tr t-foreach="offers" t-as="offer">
                                    <td>
                                        <span t-field="offer.price"/>
                                    </td>
                                </tr>
                            </tbody>
                        </table>
                    </div>
                </t>
            </t>
        </t>
    </template>
</odoo>

event_reports.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <record id="action_report_property_offers" model="ir.actions.report">
        <field name="name">Report Property Offers</field>
        <field name="model">estate.property</field>
        <field name="report_type">qweb-pdf</field>
        <field name="report_name">estate.report_property_offers</field>
        <field name="report_file">estate.report_property_offers</field>
        <field name="print_report_name">'Property Offers - %s' % (object.name or 'Attendee').replace('/','')</field>
        <field name="binding_model_id" ref="model_estate_property"/>
        <field name="binding_type">report</field>
    </record>
</odoo>

The files are well indicated in the manifest in the data part

wkhtmltopdf installation

I work on Windows 11

• According to this wiki, i have installed version 0.12.5-1
• I have downloaded the wkhtmltox-0.12.5-1.msvc2015-win64.exe version on this page
• I added in the PATH of my environment variables the following path : C:\Program Files\wkhtmltopdf\bin
• The command wkthmltopdf --version in my console gives the following result: wkhtmltopdf 0.12.5 (with patched qt)
• At that time, the pdf generation was still not working and Odoo told me every time : Unable to find Wkhtmltopdf on this system, i found this video by chance and I added in Odoo in Settings->Technical->System Parameters the following key : webkit_path : C:\Program Files\wkhtmltopdf\bin\wkhtmltopdf
• When I start my Odoo application, I see the following line in logs : INFO ? odoo.addons.base.models.ir_actions_report: Will use the Wkhtmltopdf binary at C:\Program Files\wkhtmltopdf\bin\wkhtmltopdf.exe

The problem

After all this when I click on the print button, it generates a .pdf file on my computer. The problem is that I can't open the file (with chrome for example).

When I open the .pdf file with VSCode, I see that the data is present....but in html format !

<!DOCTYPE html>
        <html lang="en-US" web-base-url="http://localhost:8069">
            <head>
                <meta charset="utf-8"/>
                <meta name="viewport" content="initial-scale=1"/>
                <title>Odoo Report</title>
                <link type="text/css" rel="stylesheet" href="/web/assets/debug/web.report_assets_common.css" data-asset-bundle="web.report_assets_common" data-asset-version="83a2b21"/>
....
                    <div class="page">
                        <h2>
                            <span>Big Villa</span>
                        </h2>
                        <div>
                            <strong>Expected Price: </strong>
                            <span>1,600,000.0</span>
                        </div>

....

How to make this file generated by Odoo is really a pdf and not html ?
Thank you in advance for your answers.