Does anyone know and have a capx on how to implement the crazy games sdk in a project.?

I have tried to follow the crazy games tutorial but I don't know how to implement the script

Yeah, you don't need a plugin, just add an empty script, paste those lines (const sdkElem ....) into the script.

Set script purpose to "Main script" on the properties panel.

After that you can insert small inline scripts into your events - to initialize the SDK, to show ads, to start/stop the gameplay etc. Here is an example from my game:

By the way, has anyone had good experience with Crazy Games? I published two games with them, but the revenue was quite poor.

Don't pay attention to all those local variables and functions, don't try to replicate my code, it won't work in your game! My screenshot was just to demonstrate how you can use small scripts in your events to call various methods from CrazyGames SDK.

For example, when a new level starts in your game, you should run this script:

crazysdk.gameplayStart();

Please refer to their documentation.