Not only would you need a PC with an OS that can read ZFS “out of the box”, more or less, but you’ll need to have familiarity with the command-line. You won’t have the same level of user-friendliness that TrueNAS offers.
You will also need to understand that once you start writing anything to the “backup” ZFS pool, it can no longer serve as a backup destination for your main pool on TrueNAS. (Unless you’re willing to undo and lose all the changes you made to the backup the next time a replication runs.)
See the last flowchart in this post.