1) First go to component -> SP page builder

2) Select the sp page that you want to add the open graph.

3) Add the selected sp page, click the options.

4) If not found option, click the Facebook icon at top left side. 

5) After that, a pop up will show and at here, enter the open graph title, upload image and fill up description. Then, click apply.

6)Click save and close the page

7) Then refresh the page and the open graph now is set.