gpg: no default secret key: No secret key

[rimmartin]

with jdk-12.0.1 and maven 3.3.9

Hi, trying to setup and run these test and hit the following build failure:

--- maven-gpg-plugin:1.5:sign (sign-artifacts) @ ldp-testsuite ---
gpg: no default secret key: No secret key
gpg: signing failed: No secret key
------------------------------------------------------------------------
BUILD FAILURE
------------------------------------------------------------------------
Total time: 18.496 s
Finished at: 2019-12-29T14:39:04-05:00
Final Memory: 28M/104M
------------------------------------------------------------------------
Failed to execute goal org.apache.maven.plugins:maven-gpg-plugin:1.5:sign (sign-artifacts) on project ldp-testsuite: Exit code: 2 -> [Help 1]

To see the full stack trace of the errors, re-run Maven with the -e switch.
Re-run Maven using the -X switch to enable full debug logging.

what need I learn about the setup and running?