Get all exchange rates

curl --request GET \
     --url https://sandboxapi.onbrails.com/api/v1/wallets/payout/rate/{currency} \
     --header 'Authorization: Bearer YOUR_SECRET_KEY' \
     --header 'accept: application/json'

{
  "status": true,
  "message": "KES rate successfully retrieved",
  "data": {
    "currency": "KES",
    "sellRate": 124.7,
    "buyRate": 130.6
  }
}