pagination for GP custom page template

Hello there,

You can try adding this CSS in Customize > Additional CSS:

.next.page-numbers span {
    display: none;
}

.next.page-numbers:after {
    content: ">";
}

previous not changes

.next.page-numbers span, .prev.page-numbers span  {
    display: none;
}

.next.page-numbers:after {
    content: ">";
}

.prev.page-numbers:before {
    content: "<";
}