My Macbook Air (M1, 2020) won't charge. I needed an update but when I got to the step to "Restart Now" it says I have to connect to power before continuing updates. The unit won't charge in the first place. What should I do?

I should follow these steps

If the battery in your Mac notebook computer won’t charge, try one or more of these solutions:

• Reset the SMC: Reset the System Management Controller (SMC), which controls how your Mac manages power. If you have a Mac with Apple silicon, just restart your computer. For other Mac computers, see the Apple Support article How to reset the SMC of your Mac.
• 
  
• Get your Mac serviced: If the battery still won’t charge, your Mac may need to be serviced. Take your Mac to your local Apple Store or contact AppleCare. See Find how to service or repair your Mac.

And if it is not working follow the last step and set your Mac up for service