index.html

<!DOCTYPE html>
<html lang="en">

    <head>
        <style>

            html {
                scrollbar-width: normal;
                scrollbar-color: #777 #555;
            }

            .title {
                size: 3em;
                display: flex;
                justify-content: center;
            }

        </style>
    </head>

    <body>
        <h1 class="title">Local storage, Read file testing</h1>
    </body>
    
    <script>

        function get_txt(name) {
            fetch(name)
            .then(response => response.text())
            .then(data => {
  	        console.log(data);
            });
        }

        function get_local(name) {
            const local = localStorage.getItem(name);
            console.log(local);
        }

        function set_local(name, value) {
            localStorage.setItem(name, value);
        }

        function remove_local(name) {
            localStorage.removeItem(name);
        }

        function clear_local() {
            localStorage.clear();
        }
        
    </script>

</html>