Yes that is my BTC address.. believe or not, that is my friend account, he is a freelancer and don' know about crypto.. i just want to help for payment and take 5% as fee.. That is doesn't matter you believe or not.. not very important when i compared to helping each other..
mulyanah20 was created on August 2018 and his first contest participation was December 2018. There's more than 4 months gap in between this. By this time, this account has some post on different boards too. So, it simply doesn’t look like the account was created for participating in the contest as you referred. More likely, the account knows how the forum works as they were discussing merit and other things when they created the account. I doubt anyone knows how the forum works but doesn’t know how to create a btc address.