Copy the override code, then go to your Assets tab, click on + and add a new override. Name it Scrollsnap and paste the code inside replacing the reference code from Framer.

Select your main frame where you want your effect and from the right panel go down to the code overrides section and click on + then select Scrollsnap file and for the override select the Container one. Make sure this main frame has Height set to Viewport height.

For the contents in your container you need to select all of them and apply again the Scrollsnap file but this time select Item override instead of Container.