This isn't giving any difference in the code when I change none to thin or auto please can someone explain why?

Question

.mytext {
width: 200px;
height: 200px;
overflow-y: auto;
/*for Firefox*/
scrollbar-width: none; /*change none to thin to check what happens*/

/*for IE and Edge*/
-ms-overflow-style: none;
}
.mytext::-webkit-scrollbar {
display: none;
}

Answer 1

.mytext::-webkit-scrollbar {
display: none;
}

On this line you are removing the scrollbar which makes so that the line above will get over writen by "display:none"