After you file your tax return, when do you have to pay the taxes?

You need to pay your balance before April 30th (May 1 since 30th is a sunday) to avoid interest and penalties.  Here are the links to the due dates or instalment payment dates.

https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/deductions-credits-expenses/[product key removed]ce-owing.html

https://www.canada.ca/en/revenue-agency/services/payments-cra/individual-payments/income-tax-instalments/due-dates.html