Set OTP delivery preference for handle login

Set your preferred OTP delivery channel when logging in via handle.

Valid values:

• "email": Prefer email OTP
• "sms": Prefer SMS OTP
• null: Clear preference (show all options)

When set, the preferred channel appears first in the available methods during handle login. This helps streamline the login flow.

Note: You must have a verified identity of the preferred type. Setting a preference for a type you don't have will have no effect.

Authentication: Authorization: Bearer <CLIENT_JWT>