what to do if i have several devices with activation locks

Inferring from your question that you can't use these devices and want to dispose of them, search for an e-waste centre in your area.

Failing that Apple offer a recycling service for old devices. Newer devices can attract a credit for purchase of new devices, but those without a cash value can still be sent for recycling using Apple's trade in plan. See: Apple Trade In.

Note the text at the head of that page: If your device isn’t eligible for credit, we’ll recycle it for free. No matter the model or condition, we can turn it into something good for you and good for the planet.

This service uses Apple stores as receiving centres or otherwise a mail-in kit can be sent.