How do you get lost in your games?

The title says it. Get lost in this context is just to be totally deep in the game, its almost like you’re flying. I have a hard time with that recently so I took a break from solo RPG and I found myself roleplaying in Character AI and I was so into the character.

I couldnt pin point why it couldn’t be like this when I play solo RPG. I also would like to not use AI when playing solo RPG as I only use it for ideas and stuff. I was wondering if I know what you guys do, maybe I can try it out and see for myself