Bit confused, you won’t get an apk for Apple carplay. Apk stands for Android package you can’t install anything android on an Apple ecosystem.
Admittedly all mine are aftermarket dashcam but none of them have the ability to remote view & need a PC. If someone is that belligerent roadside they’re probably not going to be prepared to watch a video, ultimately all that matters is you have something lolicw/insurers can view dashcam footage isn’t necessary to show the person responsible the error of their ways.
Hope you can figure it out & can work it the way you want, if not & it means that much to you maybe I can suggest a 7″ tablet to keep in the car that has a microsd slot & use microsd cards in sd card adapters in your dashcam (if the dash as doesn’t just use micro sd anyway mine do)