Can We Change Nameservers of A Custom Subdomain

You know that I had found a premium cPanel for free. That’s HelioHost, but I like InfinityFree cause it gives more quality reather then HelioHost. Anyways, acme.infinityfree.net is not working. And at least now I know that I can’t change a subdoomain nameservers. But I am not worried about that. All I have do is to get a free domain from Freenom, and change it to Bit.ly nameservers and then I can contuinue my work. (I am smart :sunglasses:) And thanks for helping me.