While Calling Rest Endpoints i am passing to uri parameters from a variable but at run time on bro

Summary

While Calling Rest Endpoints i am passing to uri parameters from a variable but at run time on browser is getting converted into %7BserviceRequest_Id%7D

Content

Json for the call created is 

"callServiceRequestRest": {
          "module": "vb/action/builtin/restAction",
          "parameters": {
            "endpoint": "crmRestApi/get_serviceRequests",
            "uriParams": {
              "fields": "\"SrNumber,Title,AccountPartyName,SrId,ProblemDescription,CriticalFlag,ProdGroupName,ProdGroupId,ProductItemDescription,InventoryItemId,InventoryOrgId,CategoryName,CategoryId,StatusCd,LastUpdateDate,LastUpdatedByDisplayName,Sector_c,Subsector_c,SeverityCd;SrStatusCdLookup:Meaning,LookupCode;SeverityCdLookup:Meaning,LookupCode\"",
              "onlyData": true,
              "serviceRequests_Id": "{{ $page.variables.serviceRequestCreatedNum }}"

            }
          }