you may have to pay tax instalment if your net tax on sale of stock is over $3,000.
https://www.canada.ca/en/revenue-agency/services/payments/payments-cra/individual-payments/income-tax-instalments/who-pays-instalments.html
Required tax instalments for individuals
Who has to pay
You may have to pay tax by instalments if your income does not have enough tax withheld or if you are self-employed, have rental or investment income, certain pension payments, or have income from more than one job.
Factors to consider
There are two factors to help determine if you have to pay tax instalments:
Province or territory where you live
The province or territory where you live on December 31 determines your net tax owing for tax instalments.
All residents (except Quebec): Option 1 of 2
If your net tax owing is more than $3,000.