It depends on the instance. Your account is on lemm.ee, and in the sidebar of lemm.ee it says that you need to wait 4 weeks.
In the meantime, you can still link to image files directly.
If you have a link to the image file:
- Posts: paste it info the URL field
- Comments or the post body: use the
format
For example: 
If you don't have a link to the image, you can upload to Imgur or something like catbox.moe
