Transport Canada has issued guidance for the Pre-load Air Cargo Targeting (PACT) Program. https://tc.canada.ca/en/programs/pre-load-air-cargo-targeting-pact#toc2-1. The new regulations are published in the Canada Gazette, Part II and will come into force on April 1, 2025.
Air carriers will be required to submit detailed cargo and flight information and some airlines have already advised that these details will be mandatory for booking as of November 1, 2024. Please check with your particular carrier for additional details.