Salutations masonavery,
Though we may not be able to speak to using Continuity Camera with a specific app, let’s be sure the feature is working as a whole on your Mac. It does look like you came through the perfect article, Continuity Camera: Use iPhone as a webcam for Mac, so if you’ve done this already and can confirm that it’s working elsewhere, no need to repeat the steps. In that case, you’d want to go right to the app’s developer or app support for additional help.
Choose your iPhone as your camera or microphone
When your iPhone is properly mounted, its camera and mic are available to apps that can use them.
Choose your iPhone camera
Open FaceTime or another app to use with your iPhone camera. If the app doesn't automatically begin using it, choose your iPhone camera from the app's video menu, camera menu, or other setting. For example, in FaceTime your iPhone camera is available from the Video menu.
Choose your iPhone microphone
Your iPhone mic is available separately to apps that offer a mic setting. Or you can choose Apple menu > System Settings, click Sound in the sidebar, then select your iPhone mic in the Input tab.
You don't need to choose your iPhone mic, unless your Mac has no built-in or external mic. Your app might then choose your iPhone mic automatically.
Privacy. While the camera or mic is in use, a privacy indicator appears in the iPhone status bar and next to Control Center in the Mac menu bar. When used wirelessly, iPhone plays a brief sound when an app begins using its camera or mic.
To reach out to the app’s developers or app support you can typically find that information in the App Store. How to contact an app developer Here’s the link we found for that - Telestream ScreenFlow - Support
Thanks.