#myBtn {
  display: none;
  position: fixed;
  bottom: 45px;
  right: 0px;
  z-index: 99;
  border: none;
  outline: none;
  background-color: grey;
  color: white;
  cursor: pointer;
  padding: 5px;
  border-radius: 10px;
}

#myBtn:hover {
  background-color: #333;
}