I have to send a json message for fhir patient resource's, which is having the identifier element sliced into further as epiNo , and CivilNo with discriminator as "use", eg: epiNo as use="official" and civilid as use="usual"
how to send "identifier": with these two values?
When sending an instance, slicing is not visible. Slicing is something that happenes when creating a profile (i.e. a StructureDefinition instance). In your Patient instance, you'd simply have two (or maybe more) occurrences in the "identifier" array, with one having "use": "official" and one having "use": "usual"
Note that if you want specific identifiers, you may want to consider slicing by Identifier.type or Identifier.system, as there are numerous identifiers that could have a use of "official" or "usual" that aren't the ones you listed.