Hi @Chirag Shukla , thank you for posting in the Q&A forum.
Per my understanding, it's currently not supported to modify .accdb file directly in SPO, the file formats supported for previewing in SharePoint Online do not include Access file types.
Please refer to this post for more information:
Not able to open Access Database Files in SharePoint Online
As the post mentioned, the current solution is to apply modifications on the desktop.
In fact, there are many users who have similar requirement, so I would suggest you go to SharePoint UserVoice to make your suggestions to the official to improve the user experience.
Reference:
File types supported for previewing files in OneDrive, SharePoint, and Teams
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Thanks for your understanding and support. :)
Have a nice day!
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