When creating a text post, you have the option to upload a Gif, document or image to your post. Please click on this link for more information how to post and reply to a post.
To add an image go to Post and Text, then you’ll be able to upload an image by clicking on the paperclip icon. Add in your text and select the image you would like to upload.
Once selected, you will see the image uploaded and select the green arrow to upload it.