I have a problem with if statement in javaScript

I want to check if the state of show to change the innerText of the button according to it but when I run it the else statment doesnt work

let showBtn = document.querySelector('.show-more');

showBtn.onclick = function () {
    let show = false;
    if (show === false) {
        showBtn.innerText = 'Show Less';
        show = true;
    } else {
        showBtn.innerText = 'Show more';
    }
}