Hello there, @jeanmpw3. Let's work this out so you can print and complete your tasks inside QuickBooks Online (QBO).
Before anything else, may I ask if you're referring to printing a report that contains the list of checks entered inside your company? Or are you referring to the Check register inside your Chart of accounts?
If you want to print a report that contains list of checks, these are the steps:
Access your QuickBooks Online company.
On the left navigational bar, go to the Reports tab.
Select the report you want to print, and then click the Print icon beside the Email icon.
Check the printer settings, and then click the Print button.
In case you're trying to print the Check register in your COA, the option is unavailable at the moment.