Change sim to send message

I’ve got a primary sim card for personal use and an esim for my business.

I’ve set up an automation that triggers on new messages and sends one back each time.

However, my primary sim is always used. even when my business contacts send messages to my business number (esim).

How do make sure messages to my business number are being automatically replied to from my business number? Tried the default plan actiom but that didn’t work.