Disappointed you can't preview a CA directly on a wolf before you buy it? Well, you're in luck because I found a workaround!
Step 1.
Download and install Paint.NET
Step 2.
Find the custom apparel you want, open the preview window, and right click -> inspect on the breed's pose and sex that you want. Example:
Step 3.
There should be a bunch of code that opens. Near "data-image-urls=" will be a .PNG link. Copy this and it should download the PNG. (Edited to add: Make sure you don't copy the quotation marks!)
Example, underlined in red:
Step 4.
Save your wolf image and open it in Paint.NET.
Step 5.
Locate your CA image and open it in Paint.NET.
Step 6.
Go to image -> resize and resize the CA to 750x600.
Step 7.
Ctrl+A and Ctrl+C the CA image.
Step 8.
Go to your wolf's image, Ctrl+Shift+N and Ctrl+V the CA image onto the new layer. Now you can see what the CA will look like on your wolf!