Group_concat in a Custom query

I'm having a difficulty regarding creating a custom query in my development environment, I did the following query:

Insert user in H2 by UI Designer

I need to create a user registration system in BonitaSoft, I know that it is possible to add Organisations and user in the studio organization manager of BonitaSoft Studio, however I need to be added in H2 by the UI Designer interface, how can I do this? I dont know how to configure a connector to add data in H2, is there any configuration pattern? Any hint will be welcome, I have never worked directly with H2 only with BDM for this reason I do not know how to configure a connector to access the H2