Customer would like to use a different account for OneDrive URL and wishes to ensure they provide only the needed access.
The verbiage on the O365 Securlet activation form indicates the OneDrive account should belong to an 'admin' as shown below:
Although the O365 user account doesn't require the user to have O365 'admin center access' of any kind, consider using a user account that your organization deems as appropriate as it will have access to files (belonging to other users) that can be moved/quarantined to the OneDrive account/folder you designate (provided you have Policies in place to apply this type of remediation response).
The OneDrive URL provided for O365 Securlet can be any user in the O365 tenant so long as they are active and are assigned a license.
Testing confirmed a 'no admin access' OneDrive account was used successfully to quarantine files that had triggered a Policy with a quarantine remediation response.