Down load from a flash drive

Presumably your Dash Cam saves video to an SD Card. If so, you’ll need to connect at suitable SD Card reader to your iPad - or a USB SD Card Reader - for which you’ll find guidance in the [frequently overlooked] iPad User Guide:

Connect external storage devices to iPad - Apple Support

Assuming you have an iPad10, as suggested by the tags appended to your post, you might consider an Apple USB-C to SD Card Reader:

https://store.apple.com/uk/xc/product/MUFG2ZM/A

If instead you already have a USB SD Card Reader, you’ll need an appropriate USB-C Hub to connect the Card Reader, or an adapter. There are many third-party and Apple USB adapters from which to choose. For example, there is Apple’s USB-C Digital AV Multiport Adapter:

https://store.apple.com/uk/xc/product/MUF82ZM/A

Direct import of photos and videos from your camera SD Card to your Photo library is possible - subject to a couple of caveats:

• the SD Card must be correctly formatted as FAT, FAT32 or exFAT (FAT64)
• stored photos are stored within the expected DCIM folder

Import photos using Apple camera adapters - Apple Support

If you are unable to use the direct photo import feature, you can still manually access and copy photos/videos from the SD Card using the iPad’s built-in Files App. To do so, just open the Files App - and in the Sidebar you will see your SD Card in the list of Locations. If necessary, open the sidebar by tapping the sidebar icon at top-left of the Files App Window. Photos can be copied to the iPad Photo Library, or copied to a folder of your choice either on your iPad or elsewhere.