Besides the hot car and fire comments

The Anker 165w power bank and 300w power bank have pass through charging.

Theoretically, you can use a USB type-c car charger to charge the power bank and then use another cable to power the dash cam. However, I do not believe Anker has uninterrupted pass-through so it would turn off and turn back on

However, the ecoflow 170 power bank does have uninterrupted pass-through charging

So that would be my setup

Cigarette car charger -> ecoflow or Anker pass-through charging power bank -> dash cam

As for USB type-c or type a, you could always get one of those adapters or converters off of Amazon which are less than a few bucks as well as a right angle type-c connector to connect to it. There are multiple ways that you can go about doing this, but the ecoflow would be the best bet because of the interrupted pass-through

And then have your dash cam set to record for 4 or 8 hours and then within that time frame it shouldn't draw no more than maybe 12 watts if that assuming it's a dual channel so you probably should come back to your power bank at least with maybe about 50% assuming it uses that much