Repackaging Apps
If you need to test on a non-jailbroken device you should learn how to repackage an app to enable dynamic testing on it.
Use a computer with macOS to perform all the steps indicated in the article "Patching iOS Applications" from the objection Wiki. Once you're done you'll be able to patch an IPA by calling the objection command:
objection patchipa --source my-app.ipa --codesign-signature 0C2E8200Dxxxx
Finally, the app needs to be installed (sideloaded) and run with debugging communication enabled. Perform the steps from the article "Running Patched iOS Applications" from the objection Wiki (using ios-deploy).
ios-deploy --bundle Payload/my-app.app -W -d
Refer to "Installing Apps" to learn about other installation methods. Some of them doesn't require you to have a macOS.
This repackaging method is enough for most use cases. For more advanced repackaging, refer to iOS Tampering and Reverse Engineering - Patching, Repackaging and Re-Signing.