@Valentino Rivera Thanks for reaching out. Ensure that your subscription has the necessary permissions to create or update the server farm. You can check the permissions by going to the Access control (IAM) tab in the Azure portal and verifying that the subscription has the Contributor or Owner role assigned to it if not you might need to contact your Azure administrator to grant the required permissions.
Some regions might have restrictions on certain subscription types. Try creating the Function App in a different region to see if that resolves the issue.
please try and let me if the issue still persists.