You need to upload them to a picture-hosting website… such as imgur.com
Then you put the link to the screenshot(s) in your post; in Imgur, use “Direct Link”
Then you need to convert all your links to preformatted text by:
- highlighting the entire link and
- clicking on </> button (button #6 on the formatting bar)
Your link will show up as : https://i.imgur.com/Mdm2mRg.jpg