Government API 403 error: powerbi gcc endpoint api.powerbigov.us always return 403 error

To address my own inquiry, when dealing with GCC cloud customers, it's essential to engage in an interactive OAuth process to acquire the token; conventional username and password authentication is not supported. Furthermore, to obtain the correct access token, we must supply the Power BI resource ID, which differs from that of regular commercial users. In our specific situation, we must request permission from the resource located at "https://analysis.usgovcloudapi.net/powerbi/api". To ascertain the GCC endpoint and resource ID, Power BI offers a REST API. You can initiate a POST request to "https://api.powerbi.com/powerbi/globalservice/v201606/environments/[email protected]" to retrieve endpoint information for GCC cloud users.