Offcourse you can use Xapo Bitcoin wallet address on Faucethub. But Xapo have fee for incoming small transactions which is 0.00003396 BTC. So, when you will withdraw BTC from Faucethub to Xapo, 0.00003396 BTC will be charged as fee by Xapo. You can read more about Xapo fees here
https://in.xapo.com/fees/But can you tell, why you are using Xapo? There are many better Bitcoin wallets...