Click the input to type. Now right-click to open the context menu and choose "paste". Alternatively use the shortcut Ctrl+V. List blocks support "any", "random", "last", and "all" for compatibility with Scratch 2. Note that "all" only does something in the delete block. I included the set size example because it is also a common use case. Infinity gets casted to the number Infinity, no unique handling for it. It seems pasting text in these inputs is not common knowledge so I made this project for it. People typically used the join block to put text into these inputs. Other methods include backpacking blocks from projects made in Scratch 2, or editing project.json externally.