Hello there, @anna_jordana ...
I am assuming that you are a student wanting to post a picture in a discussion topic in your course. Is this correct? If so, here are a couple Guides for you to look through:
- How do I attach a file to a discussion reply as a student?
- How do I embed an image in a discussion reply as a student?
I hope these will be of help to you. Please let Community members know if you have any other questions about this...thanks! Take care, stay safe, and be well.