Step 1) Upload your screenshot to an image hosting website.
Step 2) Right-click the image and select "Copy Image Location":

Step 3) Create a new post on our forum and select the Img button:

You will see this:

Step 4) Paste the link in between the two tags the Img button created:

Step 5) Click Preview to make sure you can see your images!

Voilà!
Regards,
Kayla