Billing Events not created automatically in Project contract

Hello,

we are using Project contract and it's integration with Project Billing module

at the Project level selected the flag 'Derive Billing Parameters from Project contract'

we are not using Project manufacturing module

for Project contract Billable lines for Destination type Expense , i have initiated the shipping in the Delivery Tracking system(DTS) and now the for this contract shipping line the status is Interfaced in the shipping transaction form

Now want to deliver the contract deliverables to the customer for this try to ran the Interface Trip Stop SRS so that once it's delivered to customer , the Delivery tracking system(DTS) initiate the Billing events but in Interface Trip Stop SRS in Delivery LOV the Delivery number for contract line is missing because of this issue cannot deliver to customer and Billing events are not initiated automatically in Project contract