and who should give me the joint signature code?
The IDR applicant should have provided you with a joint signature code / reference number.
What if the application has already been completed?
In that case you will click on "Direct Consolidation Loan Applications" under "My Loan Documents" to locate you and provide you with the joint signature code you need. "Direct Consolidation Loan Applications" at "My Loan Documents" to locate and provide you with the joint signature code you need.