Is there a way to guarantee that backup files have not been changed?

Is there a way to guarantee that backup files have not been changed after they have been written to the backup storage?

I use @with = checksum in the backup job.

I wondered if the checksum value is saved in the backup so xp_restore_checksumonly will report an error if the backup file is somehow modified, but xp_restore_checksumonly  seems to do nothing.

it just returns a checksum id and file size. And the checksum id does not actually seem to be a checksum result. So I wonder what is the use of that stored procedure.

If anyone knows of a way to store the checksum values, so that I can compare the current checksum values against them to know that there was a modification, I would appreciate it.