What I do is use the "export" function of Photos to create a jpg file:
- select the picture you want
- click on "file" in the menu bar, then "export", then "export 1 photo"
- in the popup that appears, set the photo kind to JPG. You can adjust other things as you want in that menu
- click "export"
- another popup shows up that is asking where you want to store the new file. Pick a location and then click "export".
Now you need to go into the QB web page and into the new topic or post where you want the picture.
- Put your cursor in the spot where you want the picture to show up in the text.
- Click on the "insert image" icon -- a popup box comes up.
- Click on the "from computer" tab, then click on browse. That will bring up essentially a finder popup --
- Find the file you saved above, select it and then click on "open". That should bring you back to the QB popup,
- Click "upload file". Your picture should show up in the post at the location where you left the cursor.
Hope this works for you!