An invalid signature error occurs when the Hmac signature is generated incorrectly.
Please check if there are any problems with the executable program, check the vendorId, accesskey, and secretkey, as well as whether the setting time and timezone are correct, and whether the server path has been changed to a path that can actually be used.
Additionally, please refer to and check other sample codes below.
[Java Examples], [HMAC generation example]
Testing and confirmation is also possible with Restful API tools such as Postman.
[OPEN API Test Guide]