Where to find specific H1 code in Maker theme for modification?

Hello -

I have read many forums on changing the H1 heading to H2.

I understand how to do this as I’ve successfully done it with my “Add to Cart” text.

I’m specifically trying to locate this coding

Notify me when available

but cannot locate it in any of the code folders. Can someone point me to the right place/in the right direction to find this code in my Maker theme?

Thank you for any help/insight