What video format can I use?

Help
1

I have a problem using direct link video files.
What could be the problem and what are the restrictions and rules for this service?
Example links:
http://example.com/films/film.mp4
http://example.com/films/film.mkv

2

You example links respond with 404… as far as i can see these files do not exist.

3

The link was an example. It is not a direct link to the server.
[ link removed ]
Here is a direct temporary link to the file on the server.

4

You have to make sure that files are served through https!

5

[ link removed ]
This file plays perfectly

6

It’s hard to tell… but please understand that i can not debug individual files.