Change Delivery Billing Date

Hello Experts,

I want to change delivery billing date according sales order created date at Delivery process.

I made change pricing & billing date at sales order process. (MV45AFZZ->USEREXIT_MOVE_FIELD_TO_VBKD)

Now our system get goods issue date to delivery billing date. I want ro get sales order biling date to delivery billing date.

How can solve my issue?

Thanks.