Yes. RLUSD is a token on the XRP Ledger, so you need an active Trust Line to hold it.
In Girin Wallet, go to your XRP Ledger balances → Manage Tokens → Add Token → Search for RLUSD → Confirm.
Activating a Trust Line locks 0.2 XRP as an owner reserve (XRPL protocol requirement, not a Girin fee).