Angus, a couple different things I am using:

This is Bohning product that uses your picatinny rail, and your existing quiver mount to run the quiver parallel to the body of the crossbow. I’ve used one for about 3-4 years on a Carbon Express x-bow, it’s worked for me pretty well.

https://bowhunterssuperstore.com/bohning-mount-crossbow-quiver-mounting-system-p-1872801.html

You can install it up on the sight rail, but I used it on the bottom of barrel with the rail, without any problems.

Excalibur has this mount, I just got one for my Micro. It’s more than I need, but after trying to fit a couple of other short rails on there, it was the simplest solution.

https://bowhunterssuperstore.com/excalibur-rail-quiver-mount-three-sided-p-1871682.html

Haven’t put this one in the field yet, but it will get tested soon. Holes line up, and it’s solid when mounted, but a tad bulky. I may trim the excess material off in the future.