I've been sent a modified RL-24 for 2020 in 2022. Now what?

I've received a modified RL-24 dated in 2022, but describing services in 2020.

 

What should I do with this? Do I submit it with 2021's taxes or do I need to modify my already filed taxes for 2020?

Quebec taxes

Hello,

 

Complete the TP-1.R (indicate year 2020 omn top of the form) and mail it to Revenu Québec.

 

Thanks!