fix

src/app/app.module.ts

@@ -8,6 +8,7 @@ import { TournamentComponent } from './tournament/tournament.component';
 import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
 import { ApiModule } from './api/api.module';
 import { environment } from 'src/environments/environment';
+import { HttpClientModule } from '@angular/common/http';
 
 @NgModule({
   declarations: [AppComponent, ToastComponent, TournamentComponent],
@@ -15,6 +16,7 @@ import { environment } from 'src/environments/environment';
     BrowserModule,
     AppRoutingModule,
     NgbModule,
+    HttpClientModule,
     ApiModule.forRoot({
       rootUrl: environment.production ? '' : 'http://localhost:3000',
     }),