Hello Shadi Rashed,
Thanks for reaching out!
The feature you are requesting (submit form response via Graph API) is not yet available.
Since this feature/functionality is presently not available, you can submit a feature request idea using this support link, which will be monitored by Microsoft team and hey make the enhancements to Microsoft Graph APIs. I will also upvote for you.
However, the set of Graph API endpoints for Forms usage reports has been released earlier.
Roadmap Item #109557: Microsoft 365 Roadmap - See What's Coming | Microsoft 365
Hope this helps.
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