The Nightscape astro-imager has standard female T-threads on its nosepiece. So the easiest way to attach it to your scope is with an appropriate T-adapter. The following table lists the T-adapters used with different Celestron scopes
EdgeHD 8-inch OTAs
EdgeHD 9.25, 11 and 14-inch OTAs
NexStar 4SE and older C90s
If you want instead to use the camera in an eyepiece drawtube or visual back, then you need either the #93625 1.25” Universal T-adapter for a 1-1/14” eyepiece drawtube or the Barlowed version #93640 if you want to use negative projection and or have limited back focus (for example, your scope is a Newtonian reflector).
The Nightscape's nosepiece is a 2" diameter barrel, so it will fit directly into a 2" focuser.