Check if code is in the list

I have a list of codes in a text file and I need to know if the value typed in a text box is in the list.
list example:
How to make?

A solution is in Sajal's tutorial List Blocks On App Inventor | Imagnity in the topic

6. Search for an Item

That might be what you want to do Carlos.

or perhaps use the is in list Block
If thing is one of the elements of the list, returns true; otherwise, returns false.

I believe it was answered in K community. Pls ask your doubt in single community because you will get same reply in all community