Variable names only in lowercase?

I am an unexperienced Flowable user trying to build a authorization workflow for some user registration.
I would like to pass the JSON payload as-is through the flow, but I run into a problem, variable names in camelCase don’t show up in the forms. This is the case for both JSON attributes as for ‘single value’ variables.
I start my process instance with :

    ProcessInstance pi = myService.startProcess("start_aanvraag", map);

I add the JSON node with this code:

    ObjectMapper mapper = new ObjectMapper();
    JsonNode node = mapper.convertValue(model, JsonNode.class);

    runtimeService.setVariable(pi.getId(), "payload", node);

In the forms I can show values with expressions like:

${voornamen} and ${payload.attributen.huisnummertoevoeging}

but the forms do not show the values for expressions like:

${nummerLegitimatiebewijs} and ${payload.attributren.huisnummerToevoeging}

My conclusion is that I can not use camelCase in the naming of variables/attributes, am I right?
Or should I just alter the expressions a little bit?

With kind regards, Joris

No, there’s no such restriction. Many people use camelCasing for variables.

I

Should work if you have a variable named ‘nummerLegitimatiebewijs’

Is there maybe a typo there? ‘attributen’ seems to be wrongly spelled (I’m a Dutch speaker myself).

I fixed my wrongly spelled variable name, but still it was not picking it up …
Using all lowercase variables now