The Customer Login API documentation was updated to include an example on creating a login token manually and more clarification on jwt.io.

Example Payload

{
  "iss": "Your app’s Oauth client ID",
  "iat": "timestamp for when the token was issued",
  "jti": "randomly generated string",
  "operation": "customer_login",
  "store_hash": "abc123",
  "customer_id": 1234,
  "redirect_to": "/account.php",
  "request_ip": "111.222.333.444"
}