Zulip post message with custom username

The idea is:

I want to post a message to Zulip with a custom name. This can be done on any chat tool with a webhook, but apparently not with the API.
So maybe a custom webhook node can be implemented for this, or maybe it can be done via the API?

My use case:

Comment crossposts

I think it would be beneficial to add this because:

It makes the comments easier to follow than prefixing the name