Source: https://quiroz.co/turn-your-mobile-menu-hamburger-icon-into-a-menu-button-with-text/

Hamburger with text

/*------------------------------------------------*/
/*---------[GQ - MOBILE MENU BUTTON 1]------------*/
/*------------------------------------------------*/
 
    .mobile_menu_bar:before {
            background-color: #3e4555;
            padding: 2px 0px 2px 2px;
            top: 9px;
            color: #fff!important;}
    .mobile_menu_bar::after {
            font-family: Arial;
            content: "MENU";
            position: relative;
            padding: 10px 20px 10px 5px;
            background-color: #3e4555;
            color: #FFFFFF!important;
        cursor: pointer;}
    .mobile_nav.opened .mobile_menu_bar:before {
        content: "\4d";}
Code language: CSS (css)

Text without hamburger

/*------------------------------------------------*/
/*---------[GQ - MOBILE MENU BUTTON 2]------------*/
/*------------------------------------------------*/
 
    .mobile_menu_bar:before {
            display:none}
    .mobile_menu_bar::after {
            font-family: Arial;
            content: "MENU";
            position: relative;
            padding: 10px 20px 10px 20px;
            background-color: #3e4555;
            color: #FFFFFF!important;
        cursor: pointer;}
    .mobile_nav.opened .mobile_menu_bar:after {
        content: "CLOSE";}
Code language: CSS (css)