Cannot Use Another User Besides Administrator

Hello all,
I have 12.2.3 standard. The backup software is on the same server as the SQL software. I want to use another user other than administrator to backup (and yes SQL is setup to have a second user use it)). Anyway when I do a test connection everything comes back as working. When I try to run a backup it comes back that it is trying to do the backup with the administrator.
How can I change this?
Under the Connect to server I am using Microsoft SQL Server (Local)
Not sure what to do next.
Kelly W.

Hi Kelly,

Could you please provide us with more details about the issue you get? Do you receive any error message? Please send us a screenshot of the issue.

Sorry for the inconvenience.