If you worked more than50%of the time from home for a period of at least a month (four consecutive weeks) in 2021 due to COVID-19, you can claim home office expenses using the T777-s form.
You can claim a flat rate of $2 for each day that you worked at home during the 4 weeks’ period, plus any other days you worked at home in 2021 due to COVID-19, up to a maximum of $500 (you will enter no more than 250 days). You would not need any supporting documents for a flat rate method.