Hi,

Try to add the following code snippet to the Custom CSS area in Theme Settings to do this.

.xts-prod-design-icons-alt .xts-add-cart-btn>a:before {
  display: none;
}

.xts-prod-design-icons-alt .xts-product .xts-add-cart-btn>a {
  background-color: #439665;
  color: #fff;
  border-radius:0;
  padding-right:20px;
  padding-left:20px;
}

.xts-prod-design-icons-alt .xts-product .xts-add-cart-btn>a span {
  padding-right: 0!important;
  padding-left: 0!important;
  opacity: 1;
  max-width:100%;
}

.xts-action-btn.xts-style-icon-bg-text>a span {
  font-size: 14px!important;
}

Kind Regards