Holds 10 rolls of bags and has screw holes to be wall mounted, or use two sided tape/Command Strips to attach. Bag rolls are about 30mm in diameter and 61mm wide, so this dispenser might work with others.
Initially designed without the odd angled surface inside, but before that was added I found that the rolls would get stuck on each other and just "hang", and not roll downwards to be dispensed. The angled surface is supported from below with another angled surface that's steep enough to not need supports.
Dog bag rolls are 15 count of 9x13" bags per Amazon's description.
There are sacrificial supports built into the model for the opening, so you don't have to fiddle with support settings in your slicer.

Print instructions

5% infill is OK and plenty strong.
I used 0.3mm Draft settings.
There are 3 sacrificial supports that need to be removed after printing, they'll come right off.