Hi @wildcatwilly Could you please update your post with some more information so we can help you faster?
Which video tutorial are you referring to?
Typically an overlay is applied to a div with a background image (as an “overlay” or gradient is a background-image property and not an overlay per say). Another approach is to add a parent div block with position set to relative (or absolute/fixed as necessary), with an inline image in that div block and then another div block which has a higher z-index and absolute positioning that has the overlay style applied to it but that would be 3 elements instead of one one element.
Things like your read-only link & screenshots really helps us to help you faster.
Overlays or multiple backgrouds can be added to boxes elements: div, containers, sections etc. An image is just and image, no CSS possibility to add an overlay or layer backgrounds.
To do what you need to do, 2 ways:
make a div box, set dimensions, add image as background and add overlay
or
make a box, add an image inside add another box inside the first box, set it to position absolute so it’s over the image, add overlay as backgrounds