Hi @EJ
Of course, if you're using MFA, then ROPC flow obviously doesn't apply. However, you can use auth code flow for SharePoint authentication, which is no different from verifying the graph client.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.