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

https://sofiascoolcolumn.rivetgarden.com/posts/what-does-risk-adjusted-return-even-mean-for-gambling

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