First of all, to claim the age amount you must meet three requirements given below: -
To claim the age amount, you must turn 65 by the last day of the tax year for which you are filing.
To qualify, your net income must be less than $89,422, and the amount you may claim varies depending on your income.
If you have declared bankruptcy in the previous year or if you ceased being a resident of Canada for income tax purposes, you are not entitled to this amount.
The age deduction (age amount) is calculated automatically if you are eligible for it. You are eligible for this amount if you were 65 years of age or older on December 31, 2021, and your net income (line 23600 of your return) is less than $90,313
For more information on the age, amount go to the link below: -