I think I found out what needs to be mailed, it is on the returns but it is soo confusing
What You Need to Mail
Form DR 1778, Colorado e-filer Attachment Form for Electronic Filing needs to be mailed with the listed documents from your Colorado income tax return. Using the e-Filer Attachment option at Colorado.gov/RevenueOnline eliminates the requirement to mail. Other state(s) income tax return(s) Mail Form DR 1778 to and listed documents: Colorado Department of Revenue 1375 Sherman Street Denver, CO 80261 Don't forget to sign this form and correct postage on the envelope.
It also says, what you need to sign
Sign and date Form DR 8453 within 1 day of acceptance. must also sign and date the form.
