Without knowing your age or specific situation is it possible you are between 60-65?
The CRA says: CPP contributions are mandatory for working CPP retirement pension recipients under age 65.
You can read more about CPP rules from the CRA here:
https://www.canada.ca/en/services/benefits/publicpensions/cpp/cpp-post-retirement/eligibility.html
This article explains CPP and EI considerations for Self Employed up to age 70.
https://turbotax.intuit.ca/tips/cpp-ei-considerations-self-employed-canadians-8648