How to slide for position Fixed

Dear admin

By using the script you sent a few days ago:

.blockclass {

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

/* Hide scrollbar for IE, Edge and Firefox */
.blockclass {
  -ms-overflow-style: none;  /* IE and Edge */
  scrollbar-width: none;  /* Firefox */

I was able to slide the menu. I can also apply it with the sticky property of Position. But with Fixed function it doesn’t work. How to fix it with fixed position

Thank you !