Easy peasy - Steps to your Canada Taxback
Around February/March of each year you will receive a T4 from each employer for the previous year. For example in February/March 2024 you receive a T4 for the tax year 2023. The Canadian tax year is from January-December.
The T4 Statement of Remuneration is a summary of the tax year where all earnings and deductions are reported to the CRA. You need this T4 from each employer you worked to be able to file your Canadian tax return.
Another option to get the tax refund from the CRA is to keep your Canadian bank account open and cash the cheque into the Canadian bank account, then move the funds out to your home country. More info here.