Formally the OneNote tab explicitly has no public documentation regarding its configuration as per :
https://learn.microsoft.com/en-us/graph/teams-configuring-builtin-tabs#onenote-tabs.
You can indeed try to reverse engineer the content or web URLs, and you may very well succeed today.
But you need to understand , and accept responsibility and the associated integration testing potential downtime as that URL format can/will change with no notification whatsoever.
If you can accept that risk & responsibility, using the oneNoteWebUrl=
QSP from the contentUrl
json node seems to be a decent key.
"configuration": {
"entityId": "00727f3d-df18-43ac-8cc9-698774312f5e",
"contentUrl": "https://www.onenote.com/teams/TabContent?notebookSource=Pick¬ebookSelfUrl=https%3A%2F%2Fwww.onenote.com%2Fapi%2Fv1.0%2FmyOrganization%2Fgroups%0076777f1c-3e3d-44ad-8206-53ba08a44cec%2Fnotes%2Fnotebooks%007-ce5c7935-0960-41f0-a5ce-e82a6d365f45&oneNoteWebUrl=https%3A%2F%2Fm365x432007.sharepoint.com%2Fsites%2FTaaP%2FSiteAssets%2FTaaP%2520Notebook¬ebookName=TaaP%20Notebook&siteUrl=https%3A%2F%2Fm365x432007.sharepoint.com%2Fsites%2FTaaP&createdTeamType=Standard&oneNoteClientUrl=https%3A%2F%2Fm365x432007.sharepoint.com%2Fsites%2FTaaP%2FSiteAssets%2FTaaP%2520Notebook¬ebookIsDefault=true&ui={locale}&tenantId={tid}&upn={userPrincipalName}&groupId={groupId}&theme={theme}&entityId={entityId}&subEntityId={subEntityId}&sessionId={sessionId}&ringId={ringId}&teamSiteUrl={teamSiteUrl}&channelType={channelType}&trackingId={appSessionId}&hostClientType={hostClientType}",
"removeUrl": "https://www.onenote.com/teams/TabRemove?notebookSource=Pick¬ebookSelfUrl=https%3A%2F%2Fwww.onenote.com%2Fapi%2Fv1.0%2FmyOrganization%2Fgroups%2F46777f1c-3e3d-44ad-8206-53ba08a44cec%2Fnotes%2Fnotebooks%2F1-ce5c7935-0960-41f0-a5ce-e82a6d365f45&oneNoteWebUrl=https%3A%2F%2Fm365x432007.sharepoint.com%2Fsites%2FTaaP%2FSiteAssets%2FTaaP%2520Notebook¬ebookName=TaaP%20Notebook&siteUrl=https%3A%2F%2Fm365x432007.sharepoint.com%2Fsites%2FTaaP&createdTeamType=Standard&oneNoteClientUrl=https%3A%2F%2Fm365x432007.sharepoint.com%2Fsites%2FTaaP%2FSiteAssets%2FTaaP%2520Notebook¬ebookIsDefault=true&ui={locale}&tenantId={tid}&upn={userPrincipalName}&groupId={groupId}&theme={theme}&entityId={entityId}&subEntityId={subEntityId}&sessionId={sessionId}&ringId={ringId}&teamSiteUrl={teamSiteUrl}&channelType={channelType}&trackingId={appSessionId}&hostClientType={hostClientType}",
"websiteUrl": "https://www.onenote.com/teams/TabRedirect?redirectUrl=https%3A%2F%2Fm365x432007.sharepoint.com%2Fsites%2FTaaP%2FSiteAssets%2FTaaP%2520Notebook",
--> `oneNoteWebUrl=https%3A%2F%2Fm365x432007.sharepoint.com%2Fsites%2FTaaP%2FSiteAssets%2FTaaP%2520Notebook'
--> urldecode
https://m365x432007.sharepoint.com/sites/TaaP/SiteAssets/TaaP%20Notebook