Hi,
For this, you'll have to convert your database to the current format used, i.e. .accdb
You can refer to this link- https://video2.skills-academy.com/en-us/office/troubleshoot/access/database-previous-version
This will help you convert your database and open it in the currently used format in Microsoft Access 365. If you face an error, you can refer to this how-to on spiceworks regarding how to fix that error.
Best Regards.