#myBtn {
  display: none;
  position: fixed;
  bottom: 30px;
  right: 35px;
  z-index: 99;
  font-size: 18px;
  border: none;
  outline: none;
  background-color: red;
  color: white;
  cursor: pointer;
  padding: 15px 11px;
  border-radius: 100px;
}

#myBtn:hover {
  background-color: #e67001;
}