We're now shuffling the order of query arguments, as
it seems that Qwant actively blocks the query order of
SearXNG.
tgp seems to be short for "test group" (look at the XHR requests the
browser sends to "https://www.qwant.com/action/ui") - its actual value
doesn't matter, as long as it's sent and at the correct position in the
query params and doesn't change too frequently