javascript save text to file script

gistfile1.txt

<textarea id="text_field_to_save">Everything from here will be saved</textarea>
<input type="text" id="filename_to_save_as" value="filename.txt" />

<script>
function save_text_as_file () {
    let text_to_save = document.getElementById( 'text_field_to_save' ).value;
    let text_to_save_as_blob = new Blob( [ text_to_save ], {
        type: "text/plain"
    } );

    let text_to_save_as_url = window.URL.createObjectURL( text_to_save_as_blob );
    let filename_to_save_as = document.getElementById( 'filename_to_save_as' ).value;

    let download_link = document.createElement( 'a' );
    download_link.download = filename_to_save_as;
    download_link.innerHTML = 'Download File';
    download_link.href = text_to_save_as_url;
    download_link.style.display = 'none';
    download_link.onclick = function ( event ) {
        document.body.removeChild( event.target );
    };

    document.body.appendChild( download_link );

    download_link.click();
}
</script>