You can get testnet USDC on Sui using a dedicated faucet provided by protocols like Turbos or Cetus that support stablecoin test assets. These tokens are not from the official USDC team but are wrapped/test versions used by Sui DeFi apps. To request them:

Go to https://testnet.turbos.finance/faucet and connect your wallet. Choose USDC and click the faucet button. You’ll receive a small testnet USDC allocation.

Alternatively, some Sui dev Discord servers (like Cetus or BlueMove) also offer manual testnet token faucets. You’ll usually need to share your testnet address in a faucet channel.

Read more: https://docs.sui.io/network/testnet

Make sure you’re connected to the correct Sui Testnet RPC and have some test SUI for gas.