#myBtn {
  display: none;
  position: fixed;
  bottom: 5px;
  /*left: 360px;*/
  right: 5px; 
  z-index: -99;
  font-size: 18px;
  border: none;
  outline: none;
  background-color: Dodgerlue;
  color: red;
  cursor: pointer;
  padding: 5px;
  border-radius: 50%;
}

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