Last I recall to record gameplay footage like a dashcam, you can use a software that offers "Shadow recording" or "Instant Replay" feature. This feature lets the software continuously record the gameplay footage in the background while you're playing, and when you press a specific button, it saves the last few minutes (usually configurable) of the recorded footage. The software then starts recording again and overwrites the previously saved footage. Some examples of software that offer this feature are NVIDIA ShadowPlay, AMD ReLive, and OBS Studio. All pc of course.