That really depends, are you looking for an actual filesystem or (for real) object level storage? Does the frontend have compatibility with s3-type endpoints?
I would recommend a vpn like tailscale to encrypt traffic and not expose your local env to the internet
Here are some self-hosted s3 compatible options: https://geekflare.com/self-hosted-s3/
Although I think you might want to reconsider your architecture here. If you’re planning on self-hosting the storage for a frontend hosted on a VPS somewhere latency is probably going to make for a pretty bad experience.
Likewise when theres a company meeting which clearly and simply lays something out and people have questions.
Example: “We are switching payroll providers, This in no way impacts you as all direct deposits have been migrated. You might see a new note on the deposits from the new payroll company.” A bunch of hands go up… Its always the same people
How could you possibly have a question?!