'An error occurred while finishing the backup' - Time Machine

New (to me) MacBook Pro -15" 2017 running Ventura 13.2.1. Copied over my data and wanted to backup the machine and get it on a backup schedule. I cannot get the backup to complete due to the following error code:

"An error occurred while finishing the backup". Not an incredibly helpful error message. Saw an earlier post the restart in safemode, then retry. I did not find the directions clear - whether they wanted me to reboot into safemode, then restart the machine and try the backup, or to try the backup while in safemode.

In the meantime, would love to have an error code so that I can understand what's really happening....

Mike