How to extract data from response params in the custom identity provider - firebase

Question

Since the latest maintenances from ConnectyCube servers, I am experiencing a new issue when I authenticate with the custom identity provider.
I use Firebase as endpoint and it return the following json file (tested with Postman) :
{
"kind": "identitytoolkit#GetAccountInfoResponse",
"users": [
{
"localId": "The uid that I want to get",
"email": "test#test.com",
"passwordHash": "xxxxxx",
"emailVerified": false,
"passwordUpdatedAt": 1607681539305,
"providerUserInfo": [
{
"providerId": "password",
"federatedId": "test#test.com",
"email": "test#test.com",
"rawId": "test#test.com"
}
],
"validSince": "1607681539",
"disabled": false,
"lastLoginAt": "1620422687374",
"createdAt": "1607681539305",
"lastRefreshAt": "2021-05-07T21:24:47.374Z"
}
]
}
Previously, to get the localId, I used the following as responses params {"uid": "#{users[0].localId}"} and it worked.
Now I get the error "base":["Custom Identity Provider uid is required"] when I try to sign in the users while nothing changed in my code.
Do you have a solution to access to the localID parameter without using [0] as it seems to be the cause of the issue?
My current settings for the custom identity provider:
ENDPOINT: https://identitytoolkit.googleapis.com/v1/accounts:lookup?key=API_WEBKEY
REQUEST HEADERS: {"Content-Type": "application/json"}
REQUEST PARAMS: {"idToken": "#{login}"}
RESPONSE PARAMS: {"uid": "#{users[0].localId}"}
Extract of my script where the error appear:
final token = await FirebaseLib().auth.currentUser.getIdToken();
createSession().then((cubeSession) {
CubeUser user = CubeUser(login: "$token", password: "");
signIn(user).then((cubeUser) {
Print("Worked!");
}).catchError((error) {});
}).catchError((error) {});

Answer 1

This should work now again
Please check