Same flagging as
chess.com. Only a slightly higher pedigree of character.
You know you can play with increment, right?
If you play without then you're basically saying to your opponent "We're playing with the alternate win condition of flagging.".
If you want that then that's how it is, if not play with increment.
Just make custom games and give yourself high increments. I play 2/8 blitz and it suits me way better than the 3/2 nonsense ;-).
Time is an essential component of the game. If you flag, you lose.