You can get some testnet coins from n0nce on this thread:
https://bitcointalk.org/index.php?topic=5467106.0 But you have to send them back once you finish using them.
And if you want to get Testnet coins without sending them back, then i would recommend this faucet:
https://freebitcoins.com/faucet/ there you can claim 0.001 tBtc/hour
And if you need a larger amount there is always the option to buy them:
https://altquick.com/exchange/market/BitcoinTestnet which i don't recommend it because these coins are supposed to be value-less, but it is good to know that anyone can buy 100 of them or more if they want.