Maybe. The rule is if it is an "ordinary and necessary" business expense. That may be different than "mandatory". Ordinary would be if the expense is typical and common for your line of work. Necessary would be if it helps to you to be more productive and effective at your job.
If
it is for a job for with you work as an "employee" receiving a
W-2, and they are not reimbursed to you, then you can deduct them as an
Unreimbursed Employee Business Form 2106. It goes on Schedule A
Itemized Deductions in the Misc section subject to a 2% of Adjusted Gross
Income threshold. If you don't itemize, then deducting them won't benefit
you.
Where do I enter job-related employee expenses? (Form
2106)
https://ttlc.intuit.com/replies/4800418
