How do I use my existing KeePass database on my new iPad without iTunes on a computer?

I'm a Linux user who bought an iPad. I'm also an Infosec pro who uses the KeePassX password manager. All my passwords are too long to type on the iPad - so I want to use my password manager on iPad. I installed MiniKeePass on the iPad - and with some difficulty (had to type in the password for one service), moved the database (.kdbx) to iPad. I used the export/share functionality to make the kdbx to make it available to MiniKeePass app.

I'm stuck here. I need to move my Key File too.

I can't find any way to get the Key File into MiniKeePass. The standard export/share functions don't seem to work for plain text files without extensions.

All the advice I got so far is "Use iTunes". I'm a Linux user; no Windows / Mac or even Wine.

Any suggestions?

The key file has a file extension: .key

I tested the following with Dropbox and an iPad running iOS 11. I deleted my existing key file for the test:

1. rename your key file with a .key extension
2. move the newly renamed key file to a shared folder in a cloud (or anything that the iPad can also access)
3. on your iPad, open the app for the folder share and find the key file
4. export the key file ...
5. one of the options should be "Open In..." tap it
6. you should get a list of apps you can copy the key file to and one of them should be MiniKeePass, tap it
7. this opens MiniKeePass with the key file listed under "Key Files"

That should work. Again, I did this from Dropbox, so another folder sharing service might behave differently.