.wp-block-group.is-style-telephone {
  position: relative;
  margin-left: 25px;
}
.wp-block-group.is-style-telephone:before {
  content: "";
  display: inline-block;
  position: absolute;
  width: 20px;
  height: 20px;
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
  background-image: url(./img/phone.svg);
  left: -25px;
  top: 3px;
}