You don't need to provide them, as eco said is just optional. Mandatory is the letter from your boss. You can find all this information in the official website.
My opinion is that it does not hurt your application, if you have the T4s or the paystubs, to submit them. The same for the foreign experience. Tpyslips are not mandatory, but if you have them in English...
Provide all you have.If you claim for 2 years Canadian work experience, and you have two years of payslips, give them. Or the T4s.