I tried chatting on some of the recommended apps on Reddit and I can confirm that none of them work.
Which bring me to the following question: How do you find people who are interested in long-term relationships online?
Note: Please don’t suggest looking in the real life.
Lots of my long-term friendships started with open-source projects. If that’s your kind of thing, it’s worth looking into. Either way it usually all boils down to a common hobby.