If you are using PvE for linux “VMs” those probably aren’t actually VMs but LXC containers. And if you are running docker in one of those, you’ve got containers in your containers.

Welcome to the club.

Nextcloud is a nice centralized system for that, you can setup shared folders that appear as a weblink that anyone can upload to, but it would require someone (likely you) to set up and maintain a LAMP stack application.

Otherwise if you want a simpler “share files between PCs” kind of application then Syncthing would be great for that. Install it on both PCs, link them, then setup a shared folder. The contents of that folder are then mirrored between the pcs.