No, I meant the pixel size, pixel pitch, not the resolution :-)
The 77D has 3.72 μm pixel size. 3.75*5=18.75, so a 3x Barlow (3x the Telescope's F/6 aperture ratio) would fit.
Be aware that you can not really capture deep-sky objects without tracking, with the exception of some brighter DSO (Double-stars like Albireo, perhaps the Orion nebula).
> . So I would need a T adapter for the camera itself and a barlow lens with T threads?
Yes, you would need
DSLR -> EF-T -> Barlow with T-threading -> Telescope focuser
Like on the image in my last post.
A lot of cheap sets are out of stock now :-(
(https://www.amazon.com/MEOPTEX-Barlow-Lens-2-Elements-Filter/dp/B07HHT5BMP)
(https://www.amazon.com/Astromania-Short-Barlow-Telescope-Eyepiece/dp/B0140UAEBA)
(Only 2x, https://www.amazon.com/Astromania-MultiCoated-M42x0-75-Interface-Telescopes/dp/B0140UACM6)
Field of view simulator -> Choose imaging mode. https://astronomy.tools/calculators/field_of_view/ (Do note this is just a simulation and does not simulate visual limits, or limits of the optics!)
Also note cheap achromatic barlows will introduce chromatic aberration. Apochromatic, ED, barlows will cost more.