Hello,
According to the new changes made to home office expenses you can claim for working from home due to covid, you will not be able to claim your office chair as an expense if you are a salaried employee or a commissioned employee. You can refer to this link below to see a list of expenses you can claim for your home office due to covid.
https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-re...
