How to pay withholding in Colorado on a 1099-R

Hi,

I moved to Colorado from California in 2020.  I am retired from the State of California.  In California, my state withholding tax was taken out of my monthly retirement check before it was sent to me by my retirement system.  They do not perform this service for withholding from any other state beside California.  Does anyone know how I would go about paying withholding tax from an out of state retirement account, reported on a 1099-R to the Colorado Department of Revenue?  Thanks for any help you can provide.  I have already been on hold with the Department of Revenue for half an hour.....

 

Debbie S.