How do I add paying for a security license and class on my taxes

It depends on whether you are an employee or self-employed and whether the license and class were required for your job.

If you are an employee receiving a W-2, then you cannot claim the license and class as an employee business expense.  Those are no longer deductible due to the Tax Cuts and Jobs Act.  However, the cost of the class may be eligible for an education credit, perhaps the Lifetime Learning Credit.  Search for 'education' at the top of your TurboTax screen to go through the education section for a possible credit.

If you are self-employed and the license and class are related to your business, then you can claim both items as a business expense.  In the Schedule C, there is a place to specifically enter license costs.  The cost of the class could be entered as a miscellaneous business expense.