As I am unable to add images here, I will try to explain it:
Go into SP Page builder and select a page to edit. On the top left click on the Facebook logo. This will give you 2 boxed to type in. If you add data here and save good, if no data is added, nothing will be saved in the next part.
After saving, click front page editor. In front page editor, click tools on the left, and then Basic Settings, scroll down to SEO, here you will see 4 boxed, the first two are ones you want to add meta data to, the last two are the ones we added data to earlier. So if there is no data in the last two, even if you add now, and save, it wont be saved in any of the boxes.
I hope this makes sense.