No, follow-up campaigns are designed to start sending the next day.
However, if you need an immediate reply, you could send a manual or API reply first, then use the follow-up campaign for everything after.
The API reference you can refer to would be: https://dedi.emailbison.com/api/reference#tag/replies/POST/api/replies/{reply_id}/reply
Note: Any reply from the lead will stop future follow-ups automatically.
