There's Eggnog

Tiny encrypted file uploading service. No ads, no BS. Any file type is allowed, with a 1 megabyte limit.

Currently hosting 80 files since Nov 14 2021.

XOR Encryption Key:

Source code: https://github.com/petabyt/eggnog
This instance is ran by Daniel C

Is there an API?

You can do a POST request. Simply use parameters file and key.

Why Eggnog?

I drank some yesterday.

How long do the files last?

A few years at least. I hope to keep my server up for a few decades, but there's no garuntee with self hosted stuff.
There is no garuntee that this will be up tomorrow.

XOR encrypted? So I can store my password file here?

NO