External SSD Power

I am having trouble with successfully connecting my SanDisk Extreme SSD. I have the Apple USB Camera adapter to supply it with power but it still says it needs more power. When I first got it, the Extreme SSD showed up in my Files with no problem but now it does not. I tried a different phone and it doesn’t work either. Should I be using a different cable? I am using an Apple USB-C to lighting cable. How can I generate more power for the SSD? Is there a better way to externally store photos from an iPhone? Someone help please :)