@Amro Eid Babafemi provides a great response.
To add to their response, I would check the below items.
- Public Access and IP Whitelisting: This error can occur when public access is not allowed on Azure App Service, or if the IP of your application is not whitelisted. You can try removing the access restrictions from the Networking page of your web app or try giving access to all by adding 0.0.0.0/01. Later, you can add restrictions based on your requirements.
- Access Restrictions: Navigate to the Networking page of your web app and check the Access Restrictions.
- Client Certificate Mode: Check the Client certificate mode in the General settings tab of your Azure web app’s Settings > Configurations. If it’s set to Require, it can throw a 403 error. Change it to Ignore.
- Application Setting: Try to set an application setting WEBSITE_WEBDEPLOY_USE_SCM and value true in Azure Portal and retry the deployment after 1 min.
- Rename Locked Files and Take App Offline: Ensure the Rename locked files and Take App offline options are enabled in the task.
- Remember, the sequence of the restrictions matters, so please check that once. If you have any blocked call before any allowed call, then it may impact. Also, this can happen from code as well, based on how you handle the errors.
If these solutions don’t work, you might want to check your code and deployment process for any issues.