Manchester United are very interested in Onana, especially since they have decided to release their main goalkeeper David De Gea, so Manchester United must be able to get a suitable replacement. Onana is indeed very good, so it is only natural that Inter Milan holds him at a high price because it is quite worth it with quality. which is owned by the players especially Onana is also still very young.
Onana got a good Champions League season with Inter Milan but Manchester United will have to take risk as the last season is a best one in Onana career and Inter Milan is a biggest club in his career too. Buying a player who has never played in a league is risky because moving to a new league requires many things to adapt to it. Onana is no longer young too as he is already 27 years old.
But on the other hand, I really doubt the Manchester United team's decision not to renew De Gea's contract, even though so far De Gea's performance is still very good and even last season his performance was still very good.
He made some serious mistakes which affected the club a lot like in Europa League matches with Sevilla and that last season is not a best one he has for Manchester United. In addition, his weakness with passing is a big reason Ten Hag does not plan to use De Gea in a next season.