The typical example for transactions is transferring money from one account to antther. Therefore the sample application based on Helidon.MP using the JACIS project stores bank account balances.
Note that the maven file included in the project refers a maven repository hosted at gitHub: "https://maven.pkg.github.com/janwiemer/jacis". This repository requires an autentification with the user name "JanWiemer" and the proper password / token / githubPAT. This information is usually providedin maven settings file. An example maven configuration and the token / to use can be found in the Installation chapter in the JACIS documentation.