If you are a W-2 employee your job-related expenses are not deductible on your federal return. Your state laws might be different.
https://ttlc.intuit.com/questions/4482873-which-federal-tax-deductions-have-been-suspended-by-tax-reform
If you are an independent contractor then you enter your business expenses on your Schedule C.
https://ttlc.intuit.com/community/taxes/discussion/how-to-contact-my-full-service-expert/00/1950947