How should I dispose of or recycle my Beats Flex and its battery?
Do not dispose of Beats Flex or its battery with household waste. When disposing of this product or its lithium-ion battery, do so in accordance with local environmental laws and guidelines. The lithium-ion battery should be serviced or recycled by Apple or an authorized service provider. For information about Apple's recycling program and collection points, visit www.apple.com/environment/.
From the official Beats Flex Wireless Earbuds manual, page 2
Have a follow-up question?
Answers from the official manual.
Common questions