How to create a torrent?

Hello! This question can seems stupid because I felt like creating a torrent was easy. But it's clear that I just cannot figure out how to create one.

I used both qBitTorrent and Transmission but none of these have been able to create a torrent.

I tested it on a simple image, I took a list of trackers that I added, I used another app to download the torrent file, and then...

"0 peers connected" none of the 2 apps tells that there is any peer connected.

I don't understand why I cannot download the torrent, while I can download all the other torrents.

Only some trackers detects that a peer is trying to download it. But nothing is moving.

Can you help me?