why vertical scroll bar without overflow code example

Example 1: remove scrollbar css

/* Hide scrollbar for Chrome, Safari and Opera */
.example::-webkit-scrollbar {
  display: none;
}

/* Hide scrollbar for IE and Edge */
.example {
  -ms-overflow-style: none;
}

Example 2: hgow to hide scroll bar and add buttons in javascript

.scoll-pane {
    width: 100%;
    height: auto;
    overflow: auto;
    outline: none;
    overflow-y: hidden;
    padding-bottom: 15px;
    -ms-overflow-style: scroll;  // IE 10+
    scrollbar-width: none;  // Firefox
}

ul {
    display: flex;
    list-style-type: none;
    padding: 0;
    margin: 0;
}

img {
    width: 300px;
    height: 180px;
}

  .scoll-pane::-webkit-scrollbar { 
  display: none;  // Safari and Chrome
  }