Sign a free SignIn request in the Xaman app — your XRPL address becomes your account. No password needed.
Approve a sign-in in the XTS Wallet app: your XRPL address becomes your account. Nothing is sent on the ledger and there is no fee. Get XTS Wallet
Sign a message in Keplr — your Coreum address becomes your account. Nothing is sent on chain and it costs no gas.