Ask your boss.
but the amount you can claim are very limited.
https://turbotax.intuit.ca/tips/rules-for-home-offices-6100
Home Offices Expenses for Employees
When you’re a salaried paid employee or commissioned paid employee, there are more restrictions for claiming your home office. You can only claim a home office expense when you’re required to pay for it by your employer; you can’t claim it if your employer reimburses you for it. Your employer must file the proper paperwork by certifying your obligation to use part of your home as an office on Form T2200, Declaration of Conditions of Employment. As well, you can’t make the same tax deductions available to the self-employed.