No Way To Send Lichess a Screenshot

I want to send a screenshot of cheating by my opponent
and hacking into the system. How do I do that????

You upload to imgur.com or similar. Just paste the link. But don't do it in the forum put it in a report.

Just for completeness sake: it's absolutely impossible that someone cheated by hacking into anything, so maybe you need to rethink that idea.

I didn't mean hacking in the normal sense. These are 'helpers' who
are given commands by Lichess when running tournaments, which
they abuse to help their friends, causing higher rated players to lose.

Twice I've lost a won game when the same helper stopped the tournament
near its end, and I watched my opponents time run out. The tournament's
link bar disappeared from the tournaments page as well. The helper both
times was named Surymas (I think), an Indian.

But my win was rigged to look that way, and I got tagged with a loss both times,
'for leaving the page'. I sent Lichess a screenshot proving that my opponent's
time ran out. They never looked at it.

Neither time was my points refunded, or win acknowledged. Basically they
won't unless it is dead obvious cheating, such as a player leaving the game to
consult the Stockfish engine.

So yes, I could post it to Imgur, but they won't look at it. If they did, there'd
be an option to upload an image right on the complaint form.

But there isn't. They just don't care. So I've stopped sending Lichess money,
which I give to chess.com now.

@DirTyrotTenpig"'for leaving the page'. I sent Lichess a screenshot proving that my opponent's
time ran out. They never looked at it.

Neither time was my points refunded, or win acknowledged"

What happened is you got disconnected from lichess and did not notice or get told by your browser. Which made your opponents clock tick down to 0 and make it seem that you won but when you exit or reload the page or click to analyse you get reconnected and see that you lost because you never got your opponents move.
you can help it by refreshing every 30 seconds during your opponents turn.
also read: lichess.org/faq#disconnection-loss
https://lichess.org/account/network

"So yes, I could post it to Imgur, but they won't look at it. If they did, there'd
be an option to upload an image right on the complaint form."

lichess does not want to store a million images so rather they allow people to embed using imgur.

"I didn't mean hacking in the normal sense. These are 'helpers' who
are given commands by Lichess when running tournaments, which
they abuse to help their friends, causing higher rated players to lose.

Twice I've lost a won game when the same helper stopped the tournament
near its end, and I watched my opponents time run out. The tournament's
link bar disappeared from the tournaments page as well. The helper both
times was named Surymas (I think), an Indian."

you can pause your own tournaments but that effect the game you are currently playing on whether it counts