Hi there! You can deduct certain expenses (including any GST/HST) you paid to earn employment income. You can do this only if your employment contract required you to pay the expenses and you did not receive an allowance for them, or the allowance you received is included in your income.
If you are employed, then you will need a signed T2200 from your employer in order to claim any employment expenses: https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-re...
