Hello Sruthi,
Follow below steps to submit the items to collection agency.
Step 1. Assign custom Write Off FM to the dunning activity. As part of this FM create the statistical document . Also ensure that the statistical document has the dunning step of the original written off document. This will help in the selection program for step 2 and 3.
Step 2: Run the release batch FP03M and in the additional selection tab select the dunning step and with statistical item.
Step 3: Run the submission batch FP03DM with the above parameters.
Let me know how you go.
Regards,
Rahul