How to create this moving overlay over the image?

Hello!
I am trying to recreate this kind of image overlay from this website: https://ovo-kuro.webflow.io/ a little bit down the website with the mask moving over the image. How do I achieve this effect?
Appreciate all help!

Do you mean where the section it’s written “Clients illuminate our path, shaping our brilliance”?

yes, exactly! I am not sure how to even call that effect

For that you just have to apply image as a background and then position with background-attachment: fixed

it works! thank you!