Mint a wallbox claim token for the onboarding session's user

curl --request POST \
  --url https://api.example.com/api/partners/v2.0/device-onboarding/{onboarding_session_id}/wallbox-claim-tokens

{
  "token": "<string>",
  "wss_url": "<string>",
  "expires_at": "2023-11-07T05:31:56Z"
}