With the recent release of webhooks, unfortunately they do not conform to Slack's formatting (which is fairly straightforward) which prevents them from being correctly ingested in to Slack. It would be great if Absorb allowed users to adjust webhook formatting so it can work across multiple platforms. Either add a selection of the destination system that changes the output format, or allow us to manually change the payload format. As of now, they are not usable.
https://forums.slackcommunity.com/s/question/0D5Hq00009P7TtwKAF/slack-webhook-returns-error-400-notext-i-know-the-webhook-is-okay-because-if-i-change-the-request-body-to-something-simple-a-test-works?language=en_US