what is the etiquette for resigning?

Why, yes.

Below 1000 - NEVER EVER RESIGN. You blundered ? Guess what, you do that all the time, and so does your opponent. If you sense you are losing, fight back and fight hard and you may still win or at least get a draw.

For example a very popular thread here in this forum is new players complaining about the rule of stalemate. They took everything the opponent had, but didnt bother to checkmate them, and at a certain point the opponent just runs out of legal moves and its a draw.

The same principle applies at higher levels, too. Hikaru Nakamura and Magnus Carlsen are infamous for fighting back hard and even winning lost positions because of that.

Not that this is an especially good game or anything, but just to show that this also happends to me on a little bit higher level than yours:

I had again butchered the opening, as I do all the time, and was on the defense for the whole game, to finally arrive in an endgame that was equal. And then my opponent blundered.

He’s absolutely right. At your level, and even plenty higher, the odds of your opponent blundering back are extremely high. That, or they might not know checkmating patterns (say they’re left with a queen and a king against your lone king, completely winning but new players may not have studied it). There’s also opportunity for stalemate, or dirty flags.

At the end of the day, if you resign, you’re 100% certain to lose. If you play on, even if you lose 80% of the time, you’ll win more games by not resigning.

I was playing a 2471 rated opponent yesterday. With 48 seconds left he was up 8 points of material and it's probably a mate in 10 or something

I managed to WIN this game, not draw it but win. Online chess is a weird thing, never resign because anything can happen

Lmao did he not take ur pawn??

Bro just played about 1 move every 15 seconds and flagged. No clue what happened but I'll take it