that's a mixed voice. to improve it you need to work on adding more chest into the balance so it doesn't get wobbly, without falling out of that mixed spot you found and getting stuck in pure chest again. It's not easy, you won't learn it overnight, I've been taking lessons for years to address this issue. Take your time, if you try to shortcut the process you will just hit a wall later on. Just focus on training a more powerful mix correctly over time - if you can take lessons with a teacher that will speed up the process a lot because they'll make sure you don't go down the wrong track and develop bad habits that catch up with you. Most of my training time has been spent undoing such habits in order to even get close to getting into this more solid mix properly.

I never said "chest resonance", when I mean "chest" I just mean that feeling of stability you get when you are in your chest voice. That's what you need to just bring up a little bit more into your mix, but even though that sounds simple it's probably going to take a good amount of time until you do it fully and correctly.