If your boat only has one D ring then you should be able to assume that the D ring is strong enough to be an attachment point.
IMPORTANT: by D ring I mean a strong metal D shaped ring. Some boats have a plastic handle which is only good enough for moving the boat about on shore.
The drogue should be on a length of line. You will need to experiment a bit to find the ideal length. As with an an ordinary anchor, the length of line will act as a shock absorber and will allow the drogue to sit at a convenient angle. The purpose of a drogue is to keep the boat head to wind (head to the waves) and to reduce the amount of down wind drift. IMPORTANT: the drogue will be affected by currents.
Best way to attach any anchor:
Have a strong painter (line) permanently attached to the bow ring.
Put the anchor over board and let out sufficient line.
Make a bight in the line that is attached to the anchor.
Attach the painter to the bight with either a sheetbend or double sheetbend.
Let further anchor line out until the sheetbend is ahead of the boat and under tension.
The length of anchor line between the sheetbend and the boat should not be under tension.
Loosely tie off/tidy up the inboard end of the anchor line.
When you want to unhitch, pull on the anchor line until the sheetbend comes aboard. Untie the sheetbend.
https://www.seaanchor.com/sea-anchor/