Hello, in order to put the "Extra"section on top of the back of the card you need to do these steps:
browse > click on one card included in the deck you want to modify > press the button “Cards…” > press the “back template” button > copy “{{Extra}}” section and place it above all the other fields.
Example
In my Ankihub deck I have this:
Etc. Etc
If I want to displace “extra” section, I should copy and paste the extra section on top of all the other fields: (see highlighted section)
This should do the trick. I hope this was helpful 