How to throw an event in the parent component?

Question

Angular

There is a parent component in which there is a method and it must be called with certain parameters, there is also a child component and it defines the key parameters that are needed in the parent method.
Parent method code:

<app-auth [certs]="cert"
                  [certPassword] = "certPassword"
                  [certAlias] = "certAlias"
                  (sendCert)="sendCertTest(certAlias, certPassword)"
        >
        </app-auth>

sendCertTest(certAlias, certPassword): any {
...
  }

Child component code:

<ng-container>
  <mat-expansion-panel *ngFor="let cert of certs.arrCertInfo; let i = index">
  ...
        <mat-form-field>
          <mat-label>Пароль</mat-label>
          <input matInput type="password" [(ngModel)]="certPassword">
        </mat-form-field>
        <button mat-stroked-button (click)="onSendCert(certs.arrAlias[i], certPassword)">Войти</button>
      </div>
...
</ng-container>

@Input() certs: UserKey;
  @Input() certPassword: any;
  @Input() certAlias: any;

  @Output() sendCert: EventEmitter<any> = new EventEmitter();
  onSendCert(certAlias, certPassword): any {
    this.certPassword = certPassword;
    this.certAlias = certAlias;
    this.sendCert.emit();
  }

Answer 1

this.sendCert.emit();- what's between the brackets, but at the moment nothing
gets here
(sendCert)="sendCertTest(certAlias, certPassword)"
certAlias, certPassword - will be undefined
Plus, the event has only one parameter.
And in general it is not clear why the same data is being sent back and forth.