Error while loading Receipt Method using customers 19 tabs FBDI

Summary:

We are trying to insert a Receipt Method using 19tabs FBDI and have populated the following sheets:
Parties
Party Sites
Account
Account Sites
Payment Method (Customer Receipt Method)

But we are encountering the below errors:

Account Site
1. The following combination of columns already exists: CUST_SITE_ORIG_SYS_REF, SET_ID, and CONFLICT_ID. Enter a unique combination.

Customer Receipt Method
1. An active bill-to site must be defined for the specified customer site.
2. The CUST_SITE_ORIG_SYS_REF isn't valid for the specified CUST_ORIG_SYSTEM_REFERENCE.
3. There are no customer site records in the HZ_IMP_ACCTSITES_T table with the specified CUST_SITE_ORIG_SYS_REF.