The "2021" version specifically refers to versions patched to work with newer firmware that blocked older service tools.

To get back to work without a costly trip to a service center, many users turn to the Canon Service Tool

The is a specialized utility designed for maintenance tasks that standard printer drivers cannot perform. Its primary function is resetting the internal "Waste Ink Absorber" counter, which triggers a lockout once it reaches a certain limit to prevent ink from leaking. Key Features of the 2021 Service Tool