@oliphant In the end, I implemented it with Integromat, using an Integromat Webhook as the event URL for Slack.
I didn’t understand what @NigelG meant until recently, you can try his approach as well. What he meant is that under your API Connector’s individual APIs, there’s a “Manually Enter API Response” option, where you can manually type in the API response you expect.
So in Slack’s case scenario, you can manually include in the “Trigger” field.
Hope this helps!