Result

css

a {/*背景はbackground-clipで*/
  font-size: 120px;
  background: url("https://picsum.photos/900/600") no-repeat;
  -webkit-background-clip: text;
  color: rgba(255, 255, 255, 0);
  text-shadow: 0 0 rgba(0, 0, 0, 0.06);
  background-size: 100% 0;
  animation: fill 2s infinite;
}

@keyframes fill {/*ローディングのアニメーション*/
  100% {
    background-size: 100% 100%;
  }

html

<a>LOADING</a>

can i use

via

filling text with image as background