I have a phone frame that shows some pictures by clicking on the various steps on the right. Now I want to switch to scrolling. Steps should not be changed by clicking more. Site scrolling should stop here instead – all images are scrolled through the device frame and site scrolling should proceed after the last image.

(function(d) {
  "use strict";
  const buttons = d.querySelectorAll(".button");
  const content = d.querySelectorAll(".content");
  const message = d.querySelector("#message");
  content.forEach((item) => {
    item.classList.add("hide");
  });
  buttons.forEach((item, index) => {
    item.classList.remove("hide");
    item.addEventListener("click", (event) => {
      hideAll();
      showDiv(item.dataset.destination, index);
    });
  });

  function hideAll() {
    content.forEach((item) => {
      item.classList.add("hide");
      item.classList.remove("show");
    });
  }

  function showDiv(targetDiv, index) {
    var targetElement = d.querySelector("#" + targetDiv);
    var targetCaption = d.querySelector("#" + targetElement.id + " img");
    targetElement.classList.add("show");
    message.innerHTML = targetCaption.dataset.caption;
  }
})(document);
.phone-row .wrap {
  position: relative;
  width: 100%;
  margin: 10px auto;
  padding: 50px;
  background: #fff;
  border-radius: 5px;
  box-shadow: rgba(149, 157, 165, 0.2) 0px 8px 24px;
  display: flex;
  -webkit-transition: all 0.5s cubic-bezier(0.68, -0.55, 0.27, 1.55) 0s;
  transition: all 0.5s cubic-bezier(0.68, -0.55, 0.27, 1.55) 0s;
}

.phone-row .wrap:hover {
  box-shadow: rgba(17, 12, 46, 0.15) 0px 48px 100px 0px;
  -webkit-transform: translateY(-5px);
  transform: translateY(-5px);
}

.phone-row .button-wrap {
  flex: 1 0 0%;
  height: 870px;
  overflow: hidden;
  margin: 10px;
  display: flex;
  border-radius: 5px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  position: relative;
  padding: 0;
}

.phone-row #message {
  position: absolute;
  right: 0;
  padding: 10px;
  background: #ccc;
  width: 40%;
  margin: 0;
  font-size: 0.9rem;
}

.phone-row .content-wrap {
  margin: auto;
  position: relative;
  width: 435px;
  height: 870px;
  overflow: hidden;
}

.phone-row .content-wrap ul {
  overflow: hidden;
  position: relative;
  width: 400px;
  height: 840px;
  padding: 0;
  margin: 20px 0 0 2px;
  list-style: none;
  border-radius: 20px;
}

.phone-row .content-wrap li {
  transition: all 0.5s ease;
}

.phone-row .content-wrap:before {
  content: "";
  position: absolute;
  width: 100%;
  height: 100%;
  margin: auto;
  top: 0;
  left: 0;
  z-index: 3;
  background: url(../images/huawei.png) no-repeat;
  background-size: contain;
  -webkit-transition: all 0.5s cubic-bezier(0.68, -0.55, 0.27, 1.55) 0s;
  transition: all 0.5s cubic-bezier(0.68, -0.55, 0.27, 1.55) 0s;
}

.phone-row .button {
  display: block;
  border: none;
  background: transparent;
  color: grey;
  padding: 2em;
  width: 100%;
  text-align: left;
  font-size: 1rem;
  font-weight: 600;
  transition: 0.3s;
  border-left: 1px solid #000;
  margin-left: 20px;
  padding-right: 45%;
}

.phone-row .button:hover,
.phone-row .button:focus {
  outline: 0;
  color: black;
  cursor: pointer;
}

.phone-row .button:focus {
  border-left: 5px solid #000;
}

.phone-row .content img {
  display: block;
  object-fit: cover;
  z-index: 999;
}

.phone-row .hide {
  transform: scale(0.0001);
  opacity: 0;
  position: absolute;
  z-index: -1;
  top: 0px;
}

.phone-row .show {
  transform: scale(1);
  position: relative;
  opacity: 1;
  z-index: 2;
  top: 0px;
}


/* small screen layout still needs to be worked out properly
It won't be workable like this and needs to be redesigned.
*/

@media screen and (max-width: 600px) {
  .phone-row .wrap {
    flex-direction: column;
  }
  .phone-row .content-wrap {
    order: 1;
  }
  .phone-row .button-wrap {
    max-width: 280px;
    width: 100%;
    margin: 10px auto;
    height: 100px;
    flex: auto;
    overflow: auto;
    justify-content: flex-start;
  }
}
<div class="row phone-row">
  <div class="wrap">
    <div class="content-wrap">
      <ul>
        <li class="content show" id="myItem1">
          <img src="https://via.placeholder.com/800" alt="Image 1" width="400" height="840" data-caption="Step1">
        </li>
        <li class="content" id="myItem2">
          <img src="https://via.placeholder.com/800" alt="Image 2" width="400" height="840" data-caption="Step2">
        </li>
        <li class="content" id="myItem3">
          <img src="https://via.placeholder.com/800" alt="Image 3" width="400" height="840" data-caption="Step3">
        </li>
        <li class="content" id="myItem4">
          <img src="https://via.placeholder.com/800" alt="Image 4" width="400" height="840" data-caption="Step5">
        </li>
        <li class="content" id="myItem5">
          <img src="https://via.placeholder.com/800" alt="Image 5" width="400" height="840" data-caption="Step5">
        </li>
      </ul>
    </div>
    <div class="button-wrap">
      <button data-destination="myItem1" class="button">Schritt 1: <br> Suche Dir einen Gegenstand, den Du verkaufen möchtest. </button>
      <button data-destination="myItem2" class="button">Schritt 2: <br> Mache ein Foto von dem Gegenstand und beschreibe Ihn kurz. </button>
      <button data-destination="myItem3" class="button">Schritt 3: <br> Starte einfach Dein Verkaufsvideo und interagiere mit der Community. </button>
      <button data-destination="myItem3" class="button">Schritt 4: <br> Beantworte Fragen zum Artikel, interagiere mit Käufern und starte Dein Geschäft. </button>
      <button data-destination="myItem3" class="button">Schritt 5: <br> Verkauft? Nachdem Du das Geld erhalten hast, verschickst Du Deinen Artikel. </button>
    </div>
  </div>
</div>

I hope someone can help me with that. Thank you very much.