Hi LAD579,
Thanks for contacting Apple Support Communities!
We understand that you're unable to power on your Beats Flex.
You can reset your Beats as outlined here if they don't turn on: Reset your Beats earphones - Apple Support
"Reset Beats Flex
- Hold down both the power button and the volume down button for 15 seconds.

2. When the LED indicator light flashes, release the buttons. Your earphones are now reset and ready to be set up with your devices again."
If you have access to another USB-C cable, you can also use that to charge your Beats.
If you're still unable to charge or power your Beats Flex on, we'd suggest that you contact Apple directly here: Contact Apple Support
We hope this helps.
Take care!