How to tie SurveyMonkey respondents to unique IDs so we can track their data across survey they fill out anonymously?

Looking to send SurveyMonkey links to ~100 users for an alpha test. It's an anonymous survey and they will be required to complete 3. We would like to be able to track their responses across all 3 surveys, but they will be completing the surveys anonymously.

Has anyone had experience with this? A coworker said there a way to add a line of code in the email recruitment feature that will create a unique respondent ID for us but I'm not finding how to do this anywhere.

Thanks!