"Allow Right-Click" chrome extension works great for pics and vids on Onlyfans. Just make sure you're downloading the highest quality versions of each. Sometimes opening the pic or vid in a new tab before saving to check is recommended.
For example:
960x1280 (just right-clicking on the image on the page) vs. 3024x4032 (opening the image from the post first, and then right-clicking on it).