I am no developer in the field but I do know the scarcity of these tBTC and there are even threads where people are charging interest for using the tBTC for some period. You have done great job by launching this thread and hope so everything will work as planned for your faucet.
I am just having one question, how do you believe that everyone who is getting free claims on your site will return the tBTC to you in the future? OR you just kept it as open minded thought and care less if the coins are returned to you or not?
Q. What is the funding source for this faucet?
Q. If someone wants to help then how one can do it? Just donate it or is there any other ways to?
I appreciate the positive feedback! Testnet coins, specifically Bitcoin testnet coins are quite scarce which is why I made this faucet as a few years ago as I found it extremely hard to get testnet coins for testing applications. I'm against people charging others for testnet coins as they are supposed to have no value other than being useful for testing applications without risking real funds.
In regard to people returning coins, I know a lot of people don't return the testnet coins after claiming them which is okay as I expect it, but it is always nice to see when someone does return the coins when they are done as it helps keep the faucet filled and keeps the testnet ecosystem alive.
To answer your other questions:
1. The funding source for my faucet was from some leftover tBTC I had as well as tBTC that was donated. For the other coins except tBCH and tGRS, I mined them on a private pool I created before I launched the faucet. If you're wondering about how I fund the faucet to keep it online, I pay around $50/month out of pocket to run the servers powering the faucet and nodes.
2. If someone would like to donate, they can here:
https://testnet-faucet.com/donate I also have 1 advertisement on each faucet page to help offset server costs, but I'm considering removing it as it doesn't generate nearly enough to help offset the monthly server costs.