How can I open slack modal during slack workflow execution step?

I am currently working on slack app with custom workflow step which is used to get some data from user during execution using modals,

I can do that using built-in forms from workflow builder like in the attached image.

Built in workflow form

However my form is more interactive and requires input fields to be changed based on user selection, to do that I am trying to consume https://slack.dev/java-slack-sdk/guides/modals API with custom workflow step.

My question is, do I have any chance to call open modal API, during custom workflow execution step: https://api.slack.com/events/workflow_step_execute ?

So far I failed to identify what can I use as triggerId during workflow step execution.

Thank you in advance and I do understand my question is complex, so will be happy to provide more information.

Unfortunately, it's not possible to trigger a modal from within a Workflow. Workflow Builder currently doesn't support conditional interactivity either. Sorry I don't have better news. On the plus side, Workflow Builder is going to see some significant upgrades this year!