I don't know what the "confirm submit option" is or does.
Sit on your hands. As long as you can get into the habit where pulling your hands out from underneath you automatically reminds you to do one last blunder check before moving, it should help.
Another possibility (only for online play, not OTB) is to keep a record of the moves on paper, even though there is no need, since the computer records the game. Get in the habit of deciding on your move, writing it down, and then just PICTURE yourself making the move on the board (WITHOUT actually doing so), then sit back and relax as if you've made your move. Quite often, in that moment of relaxation, you will suddenly realize that the move you've written down is a blunder.
This sounds like a tactics problem. Practicing tactics can help you to make better and more sound moves. A good book is 1001 by Fred Reinfeld. Only spend a few minutes on each problem and then look up the answer, Eventually you will get the hang of the theme and the problems will be easier. This can help you to look for what your opponent is planning.
I don't know what the "confirm submit option" is or does.
When you play daily chess, there is a option to have a move submit confirmation.
It was put in place for some of the same reasons you mentioned.
It can be found in daily settings.

Sit on your hands. As long as you can get into the habit where pulling your hands out from underneath you automatically reminds you to do one last blunder check before moving, it should help.
Another possibility (only for online play, not OTB) is to keep a record of the moves on paper, even though there is no need, since the computer records the game. Get in the habit of deciding on your move, writing it down, and then just PICTURE yourself making the move on the board (WITHOUT actually doing so), then sit back and relax as if you've made your move. Quite often, in that moment of relaxation, you will suddenly realize that the move you've written down is a blunder.
Yup. That's what I did. Now I spend too much time thinking lol, but I can still play OTB blitz fine. Just as I used to be able to, but better actually.
Hello. I am a 1600 ish player and, while trying to improve, think I have zeroed in on a flaw (a big one of many perhaps,) that if I could learn to stop would dramatically improve my play. I'm think I'm OK at first analyzing my opponent's move and finding checks, captures and threats, and I believe I am gaining the discipline to look at a number of choices for my move instead of the first one that comes to mind. Where I get ambushed is I don't consistently think about how my opponent will respond to my move e.g. check to see that I haven't left a piece hanging or an important square open (because I'm so focused on the brilliant move I'm about to play.) Some games I do, some I don't (or some times in a game I do and some times not.) This seems to be an even bigger challenge in two or three day per move games where you have to re-crank-up the focus each time? (I am close to deleting the chess.com app from my phone.) I am wondering if anyone knows of an exercise that would help me? Or is this just what makes chess a hard game? Tx
Do you have the confirm submit option turned on?
If you write yourself a checklist to follow each and every time before you confirm a move, it shouldn't be hard to make itia regular habit.