Importing Downloaded Material Images

I tried downloading some material images. once i downloaded how do i bring it into my material browser?

We cover inserting your own image for a material in class 6 and it’s in the class 6 notes

This is from the class 6 notes. Is this what you are referring to?
You can browse through Revits material library and load more into your project by selecting the
last icon on the bottom left. A dialog will open up with all material textures. Double click on the
material you want and It will be brought in the the open material (careful because it will
override the existing material if there is one) Could you please send me a screenshot of THE LAST ICON ON THE BOTTOM LEFT that your referring to?
Im not able to figure it out. can you please guide me through it.
I went into the materials library, clicked on duplicate materials and assets, renamed it, then clicked on the image on the right side to get to my downloaded images, and these are the responses im getting

Your material is saved in a zip file. Go to wherever the folder is saved on your computer. Select the folder then right click and select extract.

Thank you , its working now once i extracted the file.