To add a scrollable image to website, you can do these.
#1. First, add an Image Block with desired image
#2. Next, find ID of Image Block
#3. Use this code to Custom CSS. Remember to update ID
#block-yui_3_17_2_1_1739406872523_13003 {
img {
height: auto !important
}
.sqs-image-content {
overflow-y: scroll !important
}
}