How to fix this 'Google Maps JavaScript API error: InvalidKeyMapError' error in angular 6?

Question

I am using google map in my Angular 6 app.

I have been using this Google map in another project too. but recently I start another project and install angular agm. then used the API key that i used previous project. but it did not work. Said 'that it is an invalid key'. so i got new API key , but there is same problem. this is the problem that shows in browser.

Google Maps JavaScript API warning: InvalidKey https://developers.google.com/maps/documentation/javascript/error-messages#invalid-key util.js:222:33
Google Maps JavaScript API error: InvalidKeyMapError
https://developers.google.com/maps/documentation/javascript/error-messages#invalid-key-map-error js:51:110
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https://maps.googleapis.com/maps/api/js:51:110
on/this.l</<
https://maps.googleapis.com/maps-api-v3/api/js/35/8/common.js:73:375
_.qn</<
https://maps.googleapis.com/maps-api-v3/api/js/35/8/common.js:138:172
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https://maps.googleapis.com/maps-api-v3/api/js/35/8/common.js:67:82
<anonymous>
https://maps.googleapis.com/maps/api/js/AuthenticationService.Authenticate:1:22

map.component.html

<agm-map [latitude]="mapDetails.latitude" [longitude]="mapDetails.longitude" (mapClick)=" onChooseLocation($event)">
  <agm-marker [latitude]="mapDetails.latitude" [longitude]="mapDetails.longitude"></agm-marker>
</agm-map>

map.component.ts

import { Component, OnInit, Output, EventEmitter } from '@angular/core';
import { MapDetails } from '../shared/models/map-details.model';

@Component({
  selector: 'app-maps',
  templateUrl: './maps.component.html',
  styleUrls: ['./maps.component.css']
})
export class MapsComponent implements OnInit {
  mapDetails: MapDetails = new MapDetails();

  @Output() public mapClickEvent = new EventEmitter();
  constructor() { }

  ngOnInit() {
    this.mapDetails.latitude=6.9271;
    this.mapDetails.longitude=79.8612;
  }
  onChooseLocation(event){
      this.mapDetails.latitude=event.coords.lat;
      this.mapDetails.longitude=event.coords.lng;
      this.mapClickEvent.emit(this.mapDetails);

  }
}

user-layout.module.ts

import { JobDoneComponent } from './../../job-done/job-done.component';
import { RatingComponent } from './../../rating/rating.component';
import { NotificationsComponent } from './../../notifications/notifications.component';
import { ProvidedJobsComponent } from './../../provided-jobs/provided-jobs.component';
import { CompletedJobsComponent } from './../../completed-jobs/completed-jobs.component';
import { NgModule } from '@angular/core';
import { RouterModule } from '@angular/router';
import { CommonModule } from '@angular/common';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { UserLayoutRoutes } from './user-layout.routing';


import { UserProfileComponent } from '../../user-profile/user-profile.component';

import { ChartsModule } from 'ng2-charts';
import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
import { ToastrModule } from 'ngx-toastr';
import {ComplainComponent} from '../../complain/complain.component';
import { UserLogInComponent } from 'app/user-log-in/user-log-in.component';
//import {MatButtonModule, MatCheckboxModule, MatDialog, MAT_DIALOG_DATA, MatDialogConfig} from '@angular/material';
import { MatFormFieldModule,MatCardModule,MatStepperModule,MatSelectModule,MatButtonModule, MatCheckboxModule, MatInputModule,MatDatepickerModule, MatNativeDateModule, MatToolbarModule, MatSidenavModule, MatIconModule, MatListModule} from '@angular/material';
import {MatDialogModule} from '@angular/material/dialog';

import { PostJobsComponent } from '../../post-jobs/post-jobs.component';
import { PostPaymentsComponent } from '../../post-payments/post-payments.component';
import {MapsComponent} from '../../maps/maps.component';
import { DraftPostComponent } from '../../draft-post/draft-post.component';
import { JobRequestComponent } from '../../job-request/job-request.component';
import { AgmCoreModule } from '@agm/core';


@NgModule({
  imports: [
    CommonModule,
    RouterModule.forChild(UserLayoutRoutes),
    FormsModule,
    ChartsModule,
    NgbModule,
    ToastrModule.forRoot(),
    AgmCoreModule.forRoot({
      apiKey:'My_API_KEY'
    }),
    MatDialogModule,
    MatFormFieldModule,
    MatCardModule,
    MatStepperModule,
    MatSelectModule,
    MatButtonModule, 
    MatCheckboxModule, 
    MatInputModule, 
    MatNativeDateModule,
    MatToolbarModule, 
    MatSidenavModule, 
    MatIconModule, 
    MatListModule
  ],
  declarations: [
    PostJobsComponent,
    PostPaymentsComponent,
    DraftPostComponent,
    UserProfileComponent,
    JobRequestComponent,
    ComplainComponent,
    MapsComponent,
    CompletedJobsComponent,
    ProvidedJobsComponent,
    NotificationsComponent,
    JobDoneComponent,
    RatingComponent
  ],
  entryComponents: [RatingComponent]
})
export class UserLayoutModule { }

Answer 1

You might be loading Google Maps API twice, check if you are loading it in the provider

uiGmapGoogleMapApi.then(function(maps) {});

and also loading the script tag at the same time

<script src="https://maps.googleapis.com/maps/api/js"></script>

Try to remove the script tag and see if it works.