Fund the project.
The faucet runs on a server that costs real money. This is the only thing here that is not testnet play money.
Mainnet ZECu1qj7c2kr4ygv6cn0u5t5gd2kna9q48afg4hwx3reql2fhqmdt6v2pvztcy8xmmklnanlzev7vflxzn72v7eu3vgvj7c9sjwvjkhtecfj0cvryn95cyr9sana9vs07yftgeemrv9uckasjaju4wgsy69u0t6c98cqqtsu3cpmxdyc39qaaCheck the address first. Mainnet sends cannot be reversed.
Copy the address into your wallet. It arrives shielded, and it pays for the server and domain.
Want to top up the faucet itself instead? That takes testnet TAZ and costs you nothing: donate TAZ.