Cách cài đặt đơn giản là bạn chỉ cần copy toàn bộ code dán trước thẻ </body> và lưu lại là xong.
<style>.hotline-phone-ring-wrap{position:fixed;bottom:0;left:0;z-index:999999}.hotline-phone-ring{position:relative;visibility:visible;background-color:transparent;width:110px;height:110px;cursor:pointer;z-index:11;-webkit-backface-visibility:hidden;-webkit-transform:translateZ(0);transition:visibility .5s;left:0;bottom:0;display:block}.hotline-phone-ring-circle{width:85px;height:85px;top:10px;left:10px;position:absolute;background-color:transparent;border-radius:100%;border:2px solid #e60808;-webkit-animation:phonering-alo-circle-anim 1.2s infinite ease-in-out;animation:phonering-alo-circle-anim 1.2s infinite ease-in-out;transition:all .5s;-webkit-transform-origin:50% 50%;-ms-transform-origin:50% 50%;transform-origin:50% 50%;opacity:0.5}.hotline-phone-ring-circle-fill{width:55px;height:55px;top:25px;left:25px;position:absolute;background-color:rgba(230,8,8,0.7);border-radius:100%;border:2px solid transparent;-webkit-animation:phonering-alo-circle-fill-anim 2.3s infinite ease-in-out;animation:phonering-alo-circle-fill-anim 2.3s infinite ease-in-out;transition:all .5s;-webkit-transform-origin:50% 50%;-ms-transform-origin:50% 50%;transform-origin:50% 50%}.hotline-phone-ring-img-circle{background-color:#e60808;width:33px;height:33px;top:37px;left:37px;position:absolute;background-size:20px;border-radius:100%;border:2px solid transparent;-webkit-animation:phonering-alo-circle-img-anim 1s infinite ease-in-out;animation:phonering-alo-circle-img-anim 1s infinite ease-in-out;-webkit-transform-origin:50% 50%;-ms-transform-origin:50% 50%;transform-origin:50% 50%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;align-items:center;justify-content:center}.hotline-phone-ring-img-circle .pps-btn-img{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex}.hotline-phone-ring-img-circle .pps-btn-img img{width:20px;height:20px}.hotline-bar{position:absolute;background:rgba(230,8,8,0.75);height:40px;width:180px;line-height:40px;border-radius:3px;padding:0 10px;background-size:100%;cursor:pointer;transition:all 0.8s;-webkit-transition:all 0.8s;z-index:9;box-shadow:0 14px 28px rgba(0,0,0,0.25),0 10px 10px rgba(0,0,0,0.1);border-radius:50px!important;left:33px;bottom:37px}.hotline-bar > a{color:#fff;text-decoration:none;font-size:15px;font-weight:bold;text-indent:50px;display:block;letter-spacing:1px;line-height:40px;font-family:Arial}.hotline-bar > a:hover,.hotline-bar > a:active{color:#fff}@-webkit-keyframes phonering-alo-circle-anim{0%{-webkit-transform:rotate(0) scale(0.5) skew(1deg);-webkit-opacity:0.1}30%{-webkit-transform:rotate(0) scale(0.7) skew(1deg);-webkit-opacity:0.5}100%{-webkit-transform:rotate(0) scale(1) skew(1deg);-webkit-opacity:0.1}}@-webkit-keyframes phonering-alo-circle-fill-anim{0%{-webkit-transform:rotate(0) scale(0.7) skew(1deg);opacity:0.6}50%{-webkit-transform:rotate(0) scale(1) skew(1deg);opacity:0.6}100%{-webkit-transform:rotate(0) scale(0.7) skew(1deg);opacity:0.6}}@-webkit-keyframes phonering-alo-circle-img-anim{0%{-webkit-transform:rotate(0) scale(1) skew(1deg)}10%{-webkit-transform:rotate(-25deg) scale(1) skew(1deg)}20%{-webkit-transform:rotate(25deg) scale(1) skew(1deg)}30%{-webkit-transform:rotate(-25deg) scale(1) skew(1deg)}40%{-webkit-transform:rotate(25deg) scale(1) skew(1deg)}50%{-webkit-transform:rotate(0) scale(1) skew(1deg)}100%{-webkit-transform:rotate(0) scale(1) skew(1deg)}}@media (max-width:768px){.hotline-bar{display:none}}</style><div class='hotline-phone-ring-wrap'><div class='hotline-phone-ring'><div class='hotline-phone-ring-circle'></div><div class='hotline-phone-ring-circle-fill'></div><div class='hotline-phone-ring-img-circle'><a class='pps-btn-img' href='tel:0971539681' rel='noreferrer'><img alt='Gọi điện thoại' src='https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9R-HfxvDBXCr77m06T_iwpIfRyyGnYLW9x_a4uUsfugzKxS_lwhiKKzPx9WAZpw3M4SQx5-OvdFaxFInmiG34oAdQVauJp9I9g46UcQcjwRtkC7P_FLqj2E6NVVfYnKuAT1nN3Y5p5DY1/s1600/icon-call-nh.png' width='50' /></a></div></div><div class='hotline-bar'><a href='tel:0971539681' rel='noreferrer'><span class='text-hotline'>097 1539 681</span></a></div></div>