Google app script - make if condition with json data - google-apps-script

Question

I cannot find match condition with google app script
here i have json data contain "externalIds" and contain "type=organization, value=TIS-00096028"
I would like to get "value=TIS-00096028" but some data has externalIds some are not.
so i dont know what condition can fix it(I have not find "externalIds.Isempty" function or "find(externalIds)" function )
Some part of code
for(var i = 0; i < users.length; i++){
json = JSON.parse(users[i])
Logger.log(i)
Logger.log(json)
Logger.log(typeof(json))
Logger.log(JSON.stringify(users[i]))
Logger.log(typeof(JSON.stringify(users[i])))
Logger.log(json["externalIds"])
//Logger.log(typeof(json["externalIds"]))
//Logger.log(json["externalIds"][0]["value"])
if(json["externalIds"].ContenService ="null"){
empolyee_code=""
Logger.log("No empolyee_code "+empolyee_code)
}
else{
empolyee_code = json["externalIds"][0]["value"];
Logger.log("empolyee_code "+empolyee_code)
}
rows.push([users[i].name.givenName,
users[i].name.familyName,
users[i].primaryEmail,
getUserOrg(users[i].primaryEmail, users[i].orgUnitPath),
getStatus(users[i].suspended),
users[i].lastLoginTime.slice(0,10),
empolyee_code,
]);
}
In red circle i try to write some condition but not work.
In Excution log is a one json data of data.
here some json data contain "externalIds" field
{isDelegatedAdmin=false, addresses=[{formatted=DSM, type=work, primary=true}], isEnforcedIn2Sv=true, creationTime=2015-10-08T16:01:13.000Z, kind=admin#directory#user, lastLoginTime=2022-06-22T05:23:12.000Z, archived=false, suspended=false, languages=[{preference=preferred, languageCode=en}], nonEditableAliases=[a_achara#tripetch-isuzu.co.th.test-google-a.com, a_achara#g.tripetch-isuzu.co.th], isEnrolledIn2Sv=true, recoveryPhone=[phone], orgUnitPath=/Google/Tripetch (Google)/TIS, isAdmin=false, thumbnailPhotoEtag="Ap9BCC4uRt3h_SrDO0G_EX9zYVZwuEfjT_jX812ihkE/ZDtakkHxKrU_zGt1nyNxvPl7a88", agreedToTerms=true, customerId=C019gbqss, etag="Ap9BCC4uRt3h_SrDO0G_EX9zYVZwuEfjT_jX812ihkE/-E_Pbpdoymtn76EXDbsRNGh2ZWU", emails=[{address=a_achara#tripetch-isuzu.co.th, primary=true}, {address=a_achara#tripetch-isuzu.co.th.test-google-a.com}, {address=a_achara#g.tripetch-isuzu.co.th}], thumbnailPhotoUrl=https://www.google.com/s2/photos/private/AIbEiAIAAABECMrAkLP6qcXoxAEiC3ZjYXJkX3Bob3RvKig3ODk1NWNmN2ZjMDdiMmFiZmY4MmEwZjRkMTMwNTRjMmE0Y2U5YjgzMAG2IKR1qfqcYesdZgOUe5fVpfBDag, name={familyName=ANUMORN, givenName=ACHARA, fullName=ACHARA ANUMORN}, ipWhitelisted=false, externalIds=[{type=organization, value=TIS-00096028}], changePasswordAtNextLogin=false, phones=[{value=3261, type=work}], primaryEmail=a_achara#tripetch-isuzu.co.th, id=114182140133404581962, includeInGlobalAddressList=true, isMailboxSetup=true}
This is second data does not contain "externalIds":[{"value":"TIS-000xxxx","type":"organization"}]