Bug server

When I run the launcher from mincraft, and try to run a server like Hypixel, I can't, it says "Please switch to" mojang "mode to play with your original account!". I have tried a lot of things but nothing works. I would like to point out that I bought the Java edition game 2 months ago and that it did not work from the beginning

Hoping to have was clear and to the point, I wish you a good day.