Voyager customers are required to generate a p2e file of bibliographic records which indicate an electronic resource. The p2e file will be used by Alma migration to transform physical versions to electronic (Physical2Electronic). There are many ways to generate this file. One way is to use SQL to retrieve holdings and then bibs by location.
You can find here SQLs that were created by Bill Barnes with Bloomsburg University of Pennsylvania, a member of the KLN consortium.
Note that these SQLs are provided for example only.