When I was imaging with a DSLR I got this.
https://agenaastro.com/hotech-2-sca-t-adapter.html
The T-ring screws onto it and that fits into the 2" adapter on the RC. It's a very good adapter and your camera will not move.
But yes, you need to read up on how to colimate a RC telescope. Its not a easy telescope to work with if you are new to this type of telescope. If other members comment. They would recommend you to get a takahashi collimating scope which is not cheap. I have one and a howie laser.
If your on Facebook, ask your question on this group.
https://www.facebook.com/groups/943624572325939/