On mobile, header 3 shows Email, Phone by default, if you want to only display phone on small size screen, Please enter below css in wp-admin/appearance/customise/additionalCSS box.
@media (max-width: 767px){
.menu_three .contact_info .info_inner a {
display: none;
}
.menu_three .contact_info .info_inner a:first-child {
display: block;
}
.header_area.menu_three + row, .header_area.menu_three + div, .header_area.menu_three + section {
margin-top: 140px;
}
}
Above css will change below default header….

To below header.
