Unblock a previously blocked customer by phone number.

Before you call

• phone is required, with country code, for example +919999999999.
• The customer must already exist in your account.

How it works

• The customer is unblocked on all connected WhatsApp numbers.
• A "Customer unblocked by ..." note is added to the customer's chat.
• The response is an empty object.
• Fails with "Invalid customer!" if no customer has that number.