Above where you write your post there is a bar with a picture frame you can upload directly, by then clicking it then upload and then you can select an image directly from your computer or phone to post. If you want to post from yours or someone's album on this site you can click the 3 dots, the last icon will show a camera, and click, selecting it there. Hope this helps!
Warm puppy hugs!
(Also, I am not an administrator sorry for posting an answer here but I thought I can help and love assisting others!)