Payment link

Samar, while you are at it: it appears that none of the devices in my list (click Shearwater first) show up when the user is not logged in. I didn't notice this because I'm always logged in as admin while working on the site.

Is that a setting? I'm asking because normally a user account is only created when a device is registered for repair by the user.

You haven't set default WooCommerce pages, 

I am creating them, 

Create now links they will work fine, the links you created before will not work cause they are missing /checkout page url in them.

Devices are loading you can try to clear the cache of your browser or try in private browsing .