I’ll endorse Jhieminga’s observation.
When I first started posting pictures on PPRuNe, you couldn’t upload them directly - you had to host them somewhere. I used Photobucket which was inconvenient but free for a small number of pictures.
Then about three years ago, they shot themselves in the foot, when they went to an expensive subscription model and didn’t grandfather any existing images. They then compounded their mistake by blurring old images and pasting on a giant logo! Thanks but no thanks, Photobucket!
Shortly afterwards, the PPRuNe software changed. You can now upload images directly. Extremely easy - just click on the Image icon when composing a reply.
RogueOne suggested using Google Photos. You could, but it is redundant if you want to post photos on PPRuNe. A more important reason for not using it is you are probably giving up a lot of rights to your photos, possible even copyright.
I avoid Google as much as I can.