Add these codes to the Custom CSS box
Summary Items
/* Summary Counter */
.summary-item {
counter-increment: sum;
}
.summary-item .summary-title-link:before {
content: '0' counter(sum) '. ';
position: relative;
}


Mobile Menu Items
/* Mobile Menu Items */
.container.header-menu-nav-item {
counter-increment: sum;
}
.container.header-menu-nav-item .header-menu-nav-item-content:before {
content: '0' counter(sum) '. ';
position: relative;
}


Desktop Menu Items
/* Desktop Menu Items */
div.header-nav-item {
counter-increment: sum;
}
div.header-nav-item>a:before {
content: '0' counter(sum) '. ';
position: relative;
}


List Carousel
/* List Carousel */
li.user-items-list-carousel__slide.list-item {
counter-increment: sum;
}
li.user-items-list-carousel__slide.list-item h2:before {
content: '0' counter(sum) '. ';
position: relative;
}

List Simple Grid
/* List Simple Grid */
li.list-item {
counter-increment: sum;
}
li.list-item h2:before {
content: '0' counter(sum) '. ';
position: relative;
}


