Question about tax for a non us citizen making money in the us

So i want to start make social media accounts and content and join The monetization programs like TikTok and youtube. Most of these programs are not supported in my country.

i have a friend who lives in the us but is not a us citizen yet, he's gonna create the accounts and manage them in the us while i act like his editor and we split our cuts of the money.

but it got me wondering is this taxable income ? assuming these are his sole income source and let's say he makes 10k a month if it is taxable how much should we expect to pay assuming that's all he earns ($120k a year) and he keeps it all.