Google charged me $5000 in a month for using Google Place API - flutter

Question

My project is under development, Vuejs and Flutter in the frontend and Laravel is in the backend.
I am using Google place autocomplete API in this project, I made a big mistake due to not having enough knowledge of using google apiz.
After trial finished google charged $5000.
My mistakes were 2 things;
Requesting unnecessary data and not providing sessionToken
I am posting my edited codes here if anyone can check it please, I'm afraid to make mistake again.
vuejs code
mounted() {
this.$refs.focusable.focus();
let $vm = this;
var autocomplete = new google.maps.places.Autocomplete(
document.getElementById("autocomplete"),
{
componentRestrictions: { country: "ca" },
fields: ["address_components", "formatted_address", "geometry"],
types: ["address"],
bounds: new google.maps.LatLngBounds(
new google.maps.LatLng(49.246292, -123.116226)
),
//strictbounds: true,
}
);
google.maps.event.addListener(autocomplete, "place_changed", function () {
var data = autocomplete.getPlace();
let latlng = {
lat: data.geometry.location.lat(),
lng: data.geometry.location.lng(),
};
data.address_components.forEach((component) => {
if (component.types.indexOf("administrative_area_level_1") > -1) {
if ($vm.checkState(component.short_name)) {
$vm.validAddress(data, latlng);
} else {
$vm.invalidAddress(data);
}
}
});
});
},
According to google docs link I don't need to provide sessionToken for Autocomplete widget. and I think my code is correct here.
and this is my Flutter code
TextFormField(
autofocus: true,
controller: _addressController,
decoration: InputDecoration(hintText: 'Postal code'),
onChanged: (val) {
final sessionToken = Uuid.v4();
findPlace(val, sessionToken);
},
),
//get a place
void findPlace(String placeName, String sessionToken) async {
if (placeName.length > 1) {
String autoComplete =
"$googleApi?input=$placeName&types=address&components=country:ca&key=$mapKey&sessiontoken=$sessionToken";
var res = await http.get(Uri.parse(autoComplete));
Map data = jsonDecode(res.body);
var predictions = data['predictions'];
var placesList = (predictions as List)
.map((e) => PlacePredictions.fromJson(e))
.toList();
setState(() {
sToken = sessionToken;
placePredictionList = placesList;
});
}
}
// get place details using place_id
addressDetails(placeId, sessionToken) async {
String fields = 'address_component,formatted_address,geometry';
String placeDetailsUrl =
"$googleApiDetails?place_id=$placeId&fields=$fields&key=$mapKey&sessiontoken=$sessionToken";
var res = await http.get(Uri.parse(placeDetailsUrl));
Map data = jsonDecode(res.body);
}
In the above Flutter code there is a confusion for me is this sessiontoken or sessionToken I don't know how to check it and there is no any information in the Google docs.
Help really appreciated.

Answer 1

Can't post as a comment as I don't have the required rep.
But you can cap your API usage so things like these won't happen.
Read more here: https://cloud.google.com/apis/docs/capping-api-usage
In the Google Cloud console, go to the APIs & Services Dashboard page.
From the projects list, select a project or create a new one.
Click the name of the API you're interested in.
Click Quotas. If the Quotas tab is not present in the tab nav, it means the API you've selected doesn't have quotas defined.
To find the quota you want to cap, enter the appropriate properties and values in the filter_list Filter field. For example, to find the Subnetworks quota, enter Quota:Subnetworks.
Click the checkbox next to the quota you want to cap, and then click create EDIT QUOTAS.
Complete the quota change form, including the new limit that you want to set.
Click SUBMIT REQUEST.