How to make the player become an effect when he goes to a specific vanilla biome?

Yep. First of all, create a new Procedure. After, choose the event Random player tick (or something like this.). Then, put a if block condition and go into World Data (The second). Finally, you have just to take the block get biome at x y z (nameOfTheBiome). You have just to put the biome you want and to put the effect. Repeat the if for each biome (into the same procedure.).

I can't find the first procedure block, did they remove it? Is this still possible with another method?

Nevermind I figured it out, thanks!