In Process Builder, I am writing a formula for a field value. I would like it to look at a newly created attendee record's preferred email field, see if the contents of that field match the email field of existing contact records, and, if so, write the first and last name of that contact into the contact field of the attendee record. When I try to save the formula below, I get this error message: "The formula expression is invalid: Syntax error. Missing '='"
IF( [EventApi__Attendee__c].[EventApi__Preferred_Email__c] = [EventApi__Contact__c].Email, [EventApi__Contact__c].FirstName + " " + [EventApi__Contact__c].LastName, "no match found" )
Any tips on getting past the error message and getting the formula to work?