startpage.com as main search engine

[KingDave3]

[solved] - while writing this I figured it out. Maybe it helps someone to solve the same or similar problems.

I can't add it under Options -> Header -> Search for some reason. If I leave the name attribute blank: nothing happens when typing "dog" in the search field. after typing in dog, the new tab page only reloads.
When I write for example
URL field: https://startpage.com/search
Name attribute: ?q=
..it leads me to startpage.com but blank, without the stuff I typed in.
Try another one:
URL: https://startpage.com
Name attribute: /search/?q=
..it leads me to https://www.startpage.com/?%2Fsearch%2F%3Fq%3D=dog
Another one:
URL: https://startpage.com/
Name attribute: search/?q=
..it leads me to https://www.startpage.com/?search%2F%3Fq%3D=dog
So now I moved the slash and the first "%2F" vanished.

But as soon as I move "search" above, I get the blank page again. Unfortunately its needed to siplay the results and not just the search page.

Well, I just solved it. Do that:
URL: https://startpage.com/search?
Name attribute: query OR q
and it works. I am still posting this for people who have the same problem. Its not clear described.