Adding Continue & Back button to surveys
Continue and Back buttons can be added to give the audience more control to navigate through a quiz, follow the steps below to enable the buttons:
Step 1
Click on the Configure Section.
Step 2
Under general options, the Continue and Back Buttons can be found and enable by clicking on the grey toggle, see image below:

Note that the caption or name of the Continue and Back buttons can be edited by changing the "Text Button".