Hello all, you have been so helpful to this complete beginner so far, so I’m hoping you can carry on the hit rate!
Here’s the background:
We are training company with online courses. When a new user signs up, a Zap sends a new record from Thinkific to Zoho Creator and populates a new user form (form 1) with all their details including their unique user ID, date of birth, email address etc.
When they then purchase a course, a Zap creates a new record (row) in a separate Zoho form (form 2), using all their previous details from form 1, with the addition of the course name they have signed up for, usually level 1, and the course enrolment date.
We have 3 different levels of courses, levels 1, 2, and 3.
The user, having finished level 1, may then sign up for level 2, and a new ‘row’ is created via a Zap, in form 2 using all the users details, the course name, level 2, and the course enrollment date.
So now the user has 2 records (rows), one for level 1, and one for level 2.
Here’s a made-up example

Here’s where I am now getting stuck.
When a user completes a course, I am trying to set a zap to be triggered by a course completion in Thinkific to populate the course completion date (and eventually the certificate number) in the row specific to the course.
So let’s say the user completes level 1 on 30th may, the Zap needs to enter the course completion date against the correct row using the user ID and the course name (level 1) as the identifier i.e it needs to update a row by adding in the course completion date against the correct user and course.
I’m struggling to understand the steps to update an existing record, and ensure it updates the correct row based on the user ID and course name.
Could someone tell me the step please.
Thanks for you help!