Email From Collaborator Lookup

New to automations, so excuse this if it’s ignorant, but I am trying to create an automated email when a record is changed in one table. The email needs to be sent to a collaborator that is a lookup from another table. Below is a quick breakdown of our setup:

Base has two tables. One table for projects, another table for tasks. The tasks table is linked to a record within the project table, and using lookup pulls necessary data into the task table. Specifically, the project manager is a collaborator within the project table, but is a lookup on the task table.

I need to be able to notify the project manager when tasks change automatically.

TIA