If your 70mai APP shows the error"couldn't export to system album", please change the video code to H.264 in "Advanced settings". If you choose H.265, your phone need to be iphone 7, ios11above.
The videos should be downloaded to local album, then you can export them to your phone in local album.
But they couldn't be downloaded to your phone directly. Here are procedures:
First, make sure allow the permission of accessing album for 70mai APP in the settings:
Second, download the video and picture when connecting your dash cam pro, the downloaded videos are preserved in local album on 70mai APP.
Finally, enter the local album to export the videos you want.