hi stanley,
to better understand the situation, i'd like to confirm the following things:
1.do you use sharepoint online or on-premises sharepoint server?
2.do the access application created directly in desktop version? is it related to on-premises sharepoint server or sharepoint online?
3.could you let us know how do you crate the access applications and add it to sharepoint online?
4.the screenshot for the error message about "can't get the database files to be uploaded to it".
to post a picture, click use rich formatting>insert/edit media
in the thread page.
moreover, here is an article for your reference:upload an access app to a site.
best regards,
tim