There is a rank requirement for you to add image in your post.
The minimum rank requirement to post pictures is Jr. Member
Step 1 – Go to a Hosting site to upload your image – https://imgur.com/
Step 2 – Click on New Post
Step 3 – Add your picture
Step 4 – Click on Get Share Links
Step 5 – Copy BBCode
Step 6 – Paste this code on your post