You don't just get 0.03BTC for doing nothing. If something is too good to be true, that's cause it isn't true.
No I mean I did a trade, but I can see I can't swap it now?
It was quick test amount before doing a larger swap
Its better you stay off something like this before it turns to what you cannot accommodate any longer, you're testing what you're not sure about, if you're receiving a testnet bitcoin, which is mbtc, that is a different case, don't use your real money on what you're not sure about, don't trade or swap with someone that will require you of going through this process, its most likely a way to scam you, just be wise and cautioned.