You might want to take a look at https://community-scripts.github.io/ProxmoxVE/ . That’s exactly what you want, but without Docker. It uses Proxmox / LXC / VMs and is really, really awesome for selfhosting.
It’s actually quite simple - not sure how it does work under the hood, but take a look at your documents. Every insurance, employer or company has its own letterhead with logo, contact information and legalese. You just tell paperless on one document “hey, that is my insurance, please tag everything like this as insurance” and it will do that.
For everybody, who hasn’t that much of paperwork: I’m kind of doing the same, but without barcode stickers. Just scan the document into paperless and then stick it in a box or a folder. If you need the physical document sometimes in the future (which you won’t), paperless of course has the date of the scan / date of the document available. It then it quite easy to take your chronolocical sorted documents and find the one that came in on 2023-04-14