Selects the item at the given index in the given list

Not all App Inventor List Blocks appears in my blocks , is there any solutions ?

Welcome to the community. Can you post a screenshot of your problem ? Also since this is your first visit in the community please read

Welcome Remo.

Perhaps. Is your BlocksToolkit set properly

blocksToolkit to allow displaying all the components?

If not set to All, try setting the BlocksToolkit as shown. Does that help? You should now have this Block