Hi Egg!
Unfortunately a Mac is required to test iOS devices. Apple requires specific hardware to test against iOS devices.
Normally what you would do is setup a Mac machine with an Appium server running on it, connect the iOS device to the Mac, then point TC to the Appium server over your network. This is the only way to test iOS devices locally within TC.
We do have a product called BitBar that can be used to test iOS devices without having a Mac. You may want to investigate this path, as you can integrate it with TC.
https://bitbar.com/