When a process or flow interview fails, Salesforce sends a detailed flow error email to the admin who last modified the process or flow.

To change where flow error emails are sent, go to the Process Automation Settings page in Setup. Then update the Send Process or Flow Error Email To field.

To know about Apex Exception Email in Salesforce, check https://www.infallibletechie.com/2018/08/apex-exception-email-in-salesforce.html