Preparing invoice is different than generating eway bill. You can send good to job worker with a delivery challan.
E-way bill rules also require that you generate a eway bill.
Provided that where goods are sent by a principal located in one State to a jobworker located in any other State, the e-way bill shall be generated by the principal irrespective of the value of the consignment.
You need to generate eway bill and send goods with a delivery challan.