Custom Code to have Image animated from left to right on scroll

Hi there, I'm looking for some help to have a specific image scroll from left to right as it appears in the viewport. This is for Squarespace 7.1 Fluid Engine where image animations are not part of the design process, so I'll need to add a code injection and Custom CSS I think. The website isn't live yet so I can't offer a link. 

You can read this to know how to share site url with trial/unpublished site

Thank you so much for your help.

Where are the image block settings? I don't have a Design tab, I only have Custom CSS at the bottom of the Pages tab.

In the Design Tab of the Edit Image Block panel I don't have an Advanced option. Is this a feature in a higher service plan? I'm currently in the business plan.

On 8/15/2023 at 5:43 AM, kimmydesign said:

In the Design Tab of the Edit Image Block panel I don't have an Advanced option. Is this a feature in a higher service plan? I'm currently in the business plan.

When you add a section, choose this 

then add Image Block, you should able to see these options on Image Block