We are using DocuSign REST API v2, and we are using the \"Modify User Account Settings\" method
Endpoint: /accounts/{accountId}/users/{userId}/settings
Note the User Settings doc permissions comment:
Authorization required for changing the canManageAccount permission: Admin & not setting for self
So I would first check that the API user is itself an Administrator for the account. Check this by using the loginInformation method with login_settings=all
and looking for
....
"loginUserSettings": [
{
"name": "canManageAccount",
"value": "true"
},
in the response.
Also check that you are not doing a SOBO request for the Modify User Account Settings call.