The professional ID should clearly identify you, your role and the organisation you work for - we would recommend bringing your professional ID badge from your work. Professional membership cards such as the Blue Light card or other documents that clearly show this information can also be accepted.
Unfortunately documents that don’t identify you, your role or organisation cannot be used.
You can check to ensure your profession is eligible for the Local Heroes discount on the below article:
Who qualifies for the Local Heroes discount? – ATG Tickets - United Kingdom