Luis Enrique definitely has several options to find the best center forward to replace Mbappe next season. Randal Kolo Muani might be good for that position, while Goncalo Ramos is also good. I don't see much to think of as anything negative from PSG, they'll be fine I think.
There are still many players who can fill the void left by Mbappe, but the question is whether these players can do their job well or not? I think this is a question that almost everyone has when looking at the Paris Sait Germain front line that Mbappe has now left behind. This is because the expectations for the players who fill that position will be very high, because they will see Mbappe as a comparison. Although personally I don't really like comparing, some people do.
Luis Enrique is expected to be able to do his job well, especially when implementing strategies on the front lines or he must be smart if he wants to bring in new players. The reason is that this position is a very vulnerable position, because it is directly related to their goal productivity. The reason is that if they have difficulty scoring goals, then they are in big trouble.