I'm in a similar boat as you. I just turned 22 and have been working as a software developer for the past 3 years as well (interesting coincidence).
I noticed that I get the feeling of "burnout" when I'm doing things I don't enjoy. For instance, I can spend a couple months straight working on fun personal projects of mine all day every day, like the Medium.com clone I built, but if I'm spending two weeks straight fixing other peoples bugs at work I get extremely bored and am always watching the clock, looking forward to going home. I don't enjoy programming in those moments.
I would err on the side of caution when calling this burnout, though, to be honest. I think we are too young and haven't been at it long enough (no matter how dedicated we are) to really feel true burnout. We're just fatigued, demotivated, unexcited and a little annoyed (in my case).
I think a change of pace might help you, as it always helps me. Try doing something really challenging and thought-provoking. Entrepreneurship might be for you! Have you ever considered making your own startup? Got any ideas you've been neglecting? Take one of them on! You never know what might come of it. :)
Lastly, if you think programming in general just isn't for you anymore, but you love technology and would still like to be in the space, another thing you may want to consider is creating content of value for others to use and learn from. For instance, you could start a YouTube channel and talk about tech, crypto, AI, startups, etc.
Good luck!