iPad search does not work

I’m running iPadOS 14.6. I’m supposed to be able to search by dragging one finger down the centre of the iPad from the top. However, this usually produces the notification center. Occasionally it does bring up a search box but not very often. I assume I’m doing something wrong but I don’t know what. (It would have been easier if Apple simply placed a small search icon on the screen.)

Can anyone suggest what I should be doing to get a correct response? Thanks in advance.