Get token from B2C from nodejs application using user name and password

Hello,

I tried using Adal library to get a b2c token based on user name and password.

It fails with the following message : "AADSTS50049: Unknown or invalid instance."

The NodeJs code is quite simple:

var context = new AuthenticationContext(applicationConfig.authority);

context.acquireTokenWithUsernamePassword (resource, userdata.id, userdata.pwd, applicationConfig.clientId, function(err, tokenResponse) {
if (err) {
console.log('well that didn\'t work: ' + err.stack);
} else {
console.log(tokenResponse);
}
});

The applicationConfig parameters come from my b2c tenant.

I used an example from : https://github.com/AzureAD/azure-activedirectory-library-for-nodejs/tree/master/sample

Does anyone know what I'm missing ? What is the root cause of this error ?

Thank you in advance.

Regards.

David