If it’s obviously connection issues, just wait for them for about 2-3 minutes. If it isn’t, claim win.
If they have a decisive advantage, then claim a draw (or surrender) but if they are losing/drawn position, I would just take the win.
A lot of times, it is a network issue. I wait for a 100 seconds before claiming victory because that is the right thing to do. I also face network issues sometimes but when I return, the opponent has won. We should be sensitive of other people's problems too.
If you are clearly loosing I would declare it a draw
If not I would handle it like a real game (at some point the opponent would run out of time and you are winning) —> declare win
i think just wait if he doesnt come then you claim the win
“Right” as in: Morality right; or practically right?