How to populate issued by in course completion certificate

Summary:

We have a seeded report called course completion certificate. Here there is a rtf which contains a field called Issue By field to indicate who is the certificate provider. Oracle leave this field as blank to customize as per business need.

I customized this report and tried to populate "Assign As" in Add Learners in learning assignment into the Issued By field as per business requirement but I found difficult to link. Do anyone achieved this, please share the catalog or sql or guide me the steps to achieve this.

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