That's the neat thing, you kinda don't!
Jokes aside; seedvault has been.... notoriously known for both backing up only certain apps, sometimes without their app data, and even if you managed to backup app data the restore process has also been notoriously known for being...well let's call a spade a spade; doggy doo-doo.
A replacement backup service has been 'in the works' for years, but consistently placed on hold as they look for/acquire additional devs to help design it. But most of us have simply accepted backups are just not really feasible on GoS.
Your best bet is backing up via exporting data in each app individually as roughly 60% or more of apps feature some form of export feature.