This article outlines how to leverage PowerShell to locate the site, restore it, and assign the desired ownership.

Locate the deleted site

Get-SPODeletedSite -Identity <URL>

Restore the deleted site

Restore-SPODeletedSite -Identity <URL>

Assign an administrator to the site

Set-SPOUser -Site <URL> -LoginName <UPNofDesiredAdmin> -IsSiteCollectionAdmin $True

You could leverage that final cmd that I sent to assign an owner to it and retrieve that desired contents.

Note: Depending on your OneDrive retention policy (30 days OOB), if you are coming into 31 days after the user was deleted, it is possible that at some point today the OneDrive site will be moved to the recycle bin at which time the restoration job you are attempting would work.

Assign an administrator to the site

Set-SPOUser -Site <URL> -LoginName <UPNofDesiredAdmin> -IsSiteCollectionAdmin $True