Alerting to Zulip

I am attempting to send an alert to a Zulip server, which supports the slack, or API entries. However I am not certain how to send exactly the right format.

If I use the slack integration in OpenDistro, It doesn’t seem to get the “subject” into the “topic” section of Zulip. I assume the correct path forward would be a custom webhook… but maybe someone can help me translate what that would look like?

The API call could be made with curl as follows

curl -X POST https://yourZulipDomain.zulipchat.com/api/v1/messages \
    -u BOT_EMAIL_ADDRESS:BOT_API_KEY \
    --data-urlencode type=stream \
    --data-urlencode to=Denmark \
    --data-urlencode subject=Castle \
    --data-urlencode 'content=I come not, friends, to steal away your hearts.'

Ideally I would like to make the destination already contain these pieces

curl -X POST https://yourZulipDomain.zulipchat.com/api/v1/messages \
    -u BOT_EMAIL_ADDRESS:BOT_API_KEY \
    --data-urlencode type=stream \
    --data-urlencode to=Denmark \

While allowing the actual alert to then fill in both subject and content per alert. My goal would be so that all alerts going to the bot arrive in the same “to” location for my bot, while the subjectg could use templates to fill in the host name, and the content could define the alert.

Anyone have experience to get me a head start here?