Retrieve array env varibales from secrets (K8S)

I’m developing a Phoneix service that I will publish it as a docker image to be used by many consumer applications.

I need a way to let theese consumers define their own “env variables / parameters” via kubernetes secrets, I will explain :

I need the three main lists for all apps (urls, prices and locations), but for example app 1 will define one variable = LIB1 but app 2 wille define 2 variables LIB1 and LIB2

Is there some propositions for a smart way to do it ?