When right click as "Save Image" is not available, usually an image can still be saved by

"Save as" ie save the whole page.

Go to the Downloaded page FOLDER. Open it and look for the image or images from the SAVE AS html page.

Copy and paste. Use as normal.

Some websites also block RIGHT CLICKS. You can do the same as above by using your browsers menu SAVE AS or SAVE PAGE menu command.

SOME web pages have other coding preventing the image from being saved at all.