Postman pre-request script oder - does not run the requests in the order I expect - postman-pre-request-script

Question

Total postman noob. I have a script (well I don't I am trying to) to do the drudge tasks of authentication and authorization which takes 2 requests:
console.log("START");
var authenticationToken;
// Identity token
var authenticationTokenRequest = {
url: 'xxxx',
method: 'POST',
timeout: 0,
header: {
"Content-Type": "application/x-www-form-urlencoded",
"Authorization": "Basic xxxxx="
},
body: {
mode: 'urlencoded',
urlencoded: [
{key: "grant_type", value: "password"},
{key:"username", value: "xxxxx"},
{key:"password", value: "xxxx"},
]}
};
pm.sendRequest(authenticationTokenRequest, function (err, res) {
**console.log("01 send first request body");**
var responseJson = res.json();
console.log(responseJson);
pm.environment.set('ACCESS_TOKEN', responseJson['access_token']);
authenticationToken = responseJson['access_token'];
});
**console.log("Authentication token local var: " + authenticationToken);
console.log("Authorization token env var: " + pm.environment.get('ACCESS_TOKEN'));**
var authorizationTokenRequest = {
url: "xxxx",
method: "POST",
header: {
"Content-Type": "application/json",
"Authorization": "Bearer " + authenticationToken,
"Accept": "application/xxx+json"
},
body:{
tenantId: "xxx",
deviceId: "xxx"
}
}
pm.sendRequest(authorizationTokenRequest, function (err, res) {
**console.log("02 second request call");**
var responseJson = res.json();
pm.environment.set('ACCESS_TOKEN', responseJson['access_token']);
});
//
When I run this and look at the console, the console messages of the local vars show undefined. The console message for the second request shows in console before the first request. The second request depends on a value from the first.
What am I doing wrong? Thanks