Someone still pays gas; it is just not you directly. A relayer or paymaster submits the transaction and recovers the cost from the app's budget or from the tokens you are moving.
This removes a genuine onboarding barrier: needing native coin on a chain before you can touch anything you actually hold there. It is common on layer-2 networks and in account-abstraction wallets.
Read the terms, though. Sponsored flows require signing a message granting spending rights, and the fee taken in tokens can be well above the raw network cost. Check the effective rate before routing size through one.
Related: account-abstraction, smart-contract-wallet, gas-fee, token-approval