It sounds dumb when saying following words but I'd like to make a note.
Bitcoin network is operated with
Proof-of-work (PoW) algorithm, not Proof-of-Stake.
It means you can not stake your bitcoin and get staking rewards like you can with proof-of-stake (PoS) altcoins. If anyone contact you with investment invitation that you can stake your bitcoin, get too high rewards back. Such invitation is too good to be true, and does not match with Bitcoin protocol, it is a scam attempt.
On the forum, when you sign a bitcoin message (from non-custodial wallets
[1]) and stake it, it is only a proof of your ownership on that wallet, and on the account you make that post. Later, if you need to prove your ownership on that wallet, or on that account, just sign another message from the same Bitcoin address (more exactly, with same private key from which that address is derived).
[1] Custodial vs. Non Custodial Wallets - "Not your keys, not your coin" Explained.