You have event.target.input the property is value, not input
When the method is called, it receives an event object that contains a string of text from the input element. You can access this string with event.target.value inside the method
I’ve edited your post for readability. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.
You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.