The RTF field on the report must be named the same as the field in the SQL table.

Here is the field in the HQMS_COAPrintHeader table for the COA RTF 1 value.

Edit the report and add a RTF field to the COA report: 

The name of the field is extremely important.   The name MUST be the same as the name in the SQL table.

Add data to the COA RTF field to show on the COA report

Print the report and the data from the RTF field shows on the report.