x.15a2
You should be able to use the Restore Default Search Engines button to restore all default search engines.

Short of that, you may need to create a new user profile to get the default search engines, but this will certainly come with it's own set of pains.

Since this is more of a FF environment issue than specific to DDG, you may want to also ask about this on the FF forums or subReddit.
posted by x.15a2 Community Leader1 year and 10 months ago Link

anonymous
OK, the original question was more along the lines - why DDG dropped "add search engine" option - there is no mention of opensearch in the source...
posted by <hidden> • 1 year and 10 months ago Link
x.15a2
I just checked:
Received the following:[https://i.snag.gy/PxdID9.jpg]
posted by x.15a2 Community Leader1 year and 10 months ago Link
anonymous
That's not it - please see https://support.mozilla.org/en-US/kb/add.... There should be a tiny "+" on the magnifying glass icon in the search bar which would allow adding search engine (and I added DDG this way ages ago hence additional cloud settings in the URL)
posted by <hidden> • 1 year and 10 months ago Link