Hey, Dennis!
The Survey Login (Password Protection) is an action. you can add it to your survey by clicking on “Add Actions” inside of your “Edit Survey” tab, and then select “Survey Login (Password Protection) New!“.
I see that you've enabled the “Save & Continue” link within your “Advanced Options” – Great! now, when you click in to Preview your survey or click the “Publish” link to view it live, the “Save & Continue” is available in the far upper-right of the survey, blue text on a grey background.