Mbappe isn't ready to move. I haven't seen it anywhere on the news. Mbappe still has much to offer to that club and must be done before he moves. He's been paid a lot for the job and his contract hasn't expired until 2024. One year of sacrifice isn't an easy one. If Mbappe can give his all to PSG by next season, he will earn himself more respect and worth. But leaving behind an extra 1-year deal will pay him nothing but tag him a name ( impatience and pride). Even if he hasn't extended his contract, Mbappa can join Real Madrid at any time after his remaining 1 year, he knows this. For now, he hasn't spoken of a move to Real Madrid.
It is pretty known fact and he said it himself that he wants to play for another season and get paid what he is owed, or if he has to leave then in that case PSG has to pay him what he is owed for next season, which is 150 million give or take between his loyalty bonus payments combined plus the salary he is going to get at the same time. He literally said if PSG pays him 150 million, he is willing to leave now, or if they are not, then he is going to play one more season and get that 150 million and he is going to leave for free after that.
This is the ultimatum he provided and the only possible way for PSG to keep him would be paying him insane amount of money once again to offer him a long term deal. I do not think that they will want to do that in the end and will decline.