how to stop input field from restarting the string value?

hello,

I am making a note taking app and I want the input field to not start over its string value.

when I click on it and type, the string is being previewed, but when i click outside the input field and click back on it again, start typing, the string clears.

I don't want the input field to clear the string, so when the user edits their note, they can just continue from where they left off rather than starting over again.

how do I fix this?