RTP is the share of stakes a game is designed to return over a very large...

https://wiki-planet.win/index.php/What_Does_Expected_Value_Mean_in_Casino_Games_in_Plain_English%3F

RTP is the share of stakes a game is designed to return over a very large number of plays, not a promise for one session. A 96% RTP means a 4% house edge on average