How to trigger an agentic workflow through UI action

[JK9903]

Hello Everyone,

I'm trying to trigger an agentic workflow from a custom UI Action, and I need the conversation/output to appear in the Now Assist side panel not just run silently in the background.

Use case: Generating a Change Request resolution plan. The Agentic workflow should propose values for each field, and the user should be able to review and approve the plan directly in the Now Assist panel before it's applied.

What I've tried so far:

Created the trigger via the "Agentic Workflow – Channel and Status" configuration. This does generate a UI action automatically, and clicking it does kick off the use case — I can confirm execution via the sys_generative_ai_log table, and I see a now assist icon with a message as "working on this" some similar message. However, the Now Assist panel itself never opens, so the user has no visibility into the plan being generated or a way to review/approve it.
Built a Flow using the "AIA Trigger Use Case" action. This also successfully triggers the use case, but again nothing surfaces in the Now Assist panel.
Replicated an OOB UI action ("Generate Resolution Plan") that appeared to do something similar for another use case, hoping to reuse its approach for mine but this hasn't worked either.

Question: What's the correct/supported way to wire a UI action (or Flow trigger) to a Now Assist use case so that execution opens the Now Assist panel and drives the conversation there, rather than just running the use case invisibly? Is there a specific trigger type, client script event, or configuration step in AI Agent Studio that connects a UI action click to the panel UI specifically?

Any pointers official docs, similar setups, or things to check would be appreciated.

Docs/community post which I already referred
Trigger options for Agentic Workflow or AI Agent - ServiceNow Community