Help needed in setting up Notifications for Sales Invoice

Hi everyone,
I have created a notification in erpnext that sends an Email to the owner, customer and contact_email when a Sales Invoice is submitted, for which I selected the doctype ‘Sales Invoice’. But now in the sales invoice there are multiple items which can have different service start date and service end date. So I set up multiple notification that sends email to the recipient 1 day, 30 days, 60 days, 90 days before the service end date; for these notifications I selected the ‘Sales Invoice Item‘ doctype. But as I have selected Sales Invoice Item doctype for referencing the service end date, I am only able to select owner as the recipient of the emails.
Any guidance or referral to video/guide that helps me for this situation is much appreciated.
Thank you.