Like i pointed out in my earlier post in this thread, i don't think the op fully understands the information they've shared in this topic. Cash App adopted BTC a long time ago, so you can hold/buy/sell/send/receive BTC through the app, but it is not recommended to do so, for obvious reasons. So, if there is any agency that accepts payments for bills in BTC, then you could always make such payments through Cash App, by sending BTC from your app into their wallet address.
Hmm bro, even if OP doesn't know the whole story, I know what I found when I explored it more. I am even more surprised to know that they have this option, but for what haha? Like, who is really benefiting from this except the app on both sides haha?
Like, if I don't have BTC, I can buy it with fiat and then send it to the receiver, and the receiver can then get it directly in fiat after automatic conversion haha.
It's a completely useless app in my sight.