If we dont want to sell then dont sell, tell him he has to stay this season. If we do sell then put a buy back because even after next season he still has 3 years left on his contract. He hasnt even played a full season with us and is already asking for a move? How would he know what its going to be like if he hasnt even tried it, he is also only 20. He is the only out and out ST we have and brings a different skill set to Havertz which could come very handy, just because Lukaku failed in this system, doesnt mean he will. And with the whole 5 subs rule next season he will get plenty of game time, not forgetting that a player could get Covid and miss matches.
Also reading that West Ham are after another ST, so they would have him, Antonio and the other guy. Which doesnt make sense to me on why he is so desperate for a move.