You can try requesting SUI from this link: https://faucet.n1stake.com/. It may help if the usual source is full.

If the SUI faucet for the testnet is always full and you're unable to receive tokens, you can still get around this limitation by trying a few alternative methods. First, make sure you’re using a different wallet address and try accessing the faucet during off-peak hours, like late night or early morning UTC. If that still doesn’t work, check the official SUI Discord or developer forums users and admins often share temporary faucet alternatives or may manually send you testnet SUI if you ask in the right channel. Another option is to look for community run faucets or GitHub repos that offer small testnet allocations. Keep in mind, since demand is high, it’s best to act fast when a working faucet is available.

Read more about getting SUI testnet tokens