Random item for get background image is not working

Hi there,
I straightforward to explain,why does the random list item of getting background image are not working?

Here’s the project
https://x.thunkable.com/projects/5d9f24afe58f3829ac25579f/08c89a70-a240-4f1b-8013-5b839a1f23d1/blocks

There shouldn’t be a ‘join’ block in these blocks.
If you want to add multiple items to your list, click the blue gear icon in the ‘list’ block and add more slots to your list.

If you’re referring to a list of the same items multiple times, you should create a variable which is a list of these items, then refer to the variable.

Oh,thanks for your advance.:smile: