Maybe try puzzles that helps me find the best moves quicker or even better puzzle rush. But I don’t really know because they usually end in a mate or like the boy blunders something obvious in early puzzles
Landing the final blow in a winning position

I feel like that’s why you couldn’t convert that position. It’s your time management. If you want to play positions like that, you probably would benefit from playing slower games where you can afford to spend all that time on h4. But if you want to play blitz games, you can’t play moves that take three minutes.

I think something like queen to g4 would have been fine, just because its pretty safe as far as I can tell. A lot of times imo when playing blitz its fine to just keep your position strong or safe in order to keep moving as long as it doesn't lose tempo. I do think in a 3 minute game you can only really slow down to 6-7 seconds per move in a 5 move series. but only if its crucial. and a lot of the time calculating for 1 move is not going to get you anywhere because things are so chaotic/dynamic in blitz and your opponent is also able to calculate without losing any time. Imo that was not enough of guaranteed situation to spend more than 15 seconds on the move.
Just a few remarks :
i)Wrong king move. If the plan is h4 then Kg2 and Rh1 is correct, not Kh2 and Rg1.
ii) You have to calculate concretely a forced line in such a sharp position in order to win. If after a minute you can't find anything you have to switch to a simple good move, like 26. Qg4 as said above. You have to stay practical.
iii) In the pratical department also, you are already pawn up with a big positional advantage. You don't need to attack immediately to win the game. If you can't calculate a forced win or unsure how to proceed you can simply play slowly, you don't need to burn your bridges or go into chaos. eg 20. Qe2, then c3, Rad1, d4, and so on.

This game seems to be a bad illustration of the topic at hand. Was there really any point in this game when white is clearly winning? I don't think so.
After 24 moves you have an extra pawn and can lock down the g file. Instead of Kf1 (blocking the queen and a-rook from the g file, play 25 Kf3 and then you can plan on playing 26 Rg7, 27 Qg1, 28 Qg6, 29 Rg1
After you play 25 Kf1 then you need to take control of the g file with Qg5 on move 26 (okay) or 27 (better) so that you can play Ke2 to give your a-rook access to the g file.
In my games, I often reach positions that I sense as winning (and the computer often agrees), but just fail to land the final blow that ends the game. Often the opponent wriggles away. It is not because I blitz out moves, on the contrary I take my time yet fail to find the winning tactical blow. Later I play some suboptimal moves because of time pressure and squander my advantage. How to solve this? See this game for example.