Billing Data Not Getting Loaded In RMCS as no Billed Amount is Reflected for the Contract

Summary:

We are trying to upload Customer Contract Billing Lines in RMCS using FBDI for the AR Invoices which already billed in Legacy system (EBS) , while doing this when we check VRM_BILLING_DATA_DETAILS table we see data in this table but lines not getting processed it shows status as "NOT_PROCESSED"

Due to which billed amount does not get updated in Fusion RMCS contract .

I want to check on below 2 points

1.Can we upload Already billed lines in EBS using Billing line FBDI in Fusion as source system as EBS ?

2. where can we see error for the lines which are not processed , do we have any table which records error reason in RMCS ?