How to do validation with mat-checkbox?

I would like to know how to check if the checkbox was selected, if it was not selected, an error message will appear for the user. I managed to put the error message but not to able to use it along with the rest of the form. can you help me? Here's what I have to do.

<mat-checkbox class="hcs-full-width" [formControl]="termsFormControl"> Aceite os termos de uso

</mat-checkbox>
<mat-error *ngIf="termsFormControl.hasError('required')">
    Termo é
    <strong>requirido</strong>
</mat-error>

.ts

export class AppComponent implements OnInit {

  private subscription: Subscription;
  uri: string;
  ssid: string;
  sessiondId: string;
  ip: string;
  mac: string;
  ufi: string;
  mgmtBaseUrl: string;
  clientRedirectUrl: string;
  req: string;
  userName: string;
  hmac: string;

  name: string;
  email: string;

  constructor(@Inject(DOCUMENT) private document: any, private route: ActivatedRoute) {
  }

  ngOnInit() {
    this.route.queryParams
      .filter(params => params.mac)
      .subscribe(params => {
        console.log(params);

        this.ssid = params.ssid;
        this.sessiondId = params.sessionId;
        this.ip = params.ip;
        this.mac = params.mac;
        this.ufi = params.ufi;
        this.mgmtBaseUrl = params.mgmtBaseUrl;
        this.clientRedirectUrl = params.clientRedirectUrl;
        this.req = params.req;
        this.hmac = params.hmac;
      });
      console.log("LOGAR: " + this.nameFormControl.valid);
    console.log("LOGAR: " + this.termsFormControl.valid);
  }

  Logar() {
    if (this.nameFormControl.valid && this.emailFormControl.valid && this.termsFormControl.valid) {
      this.userName = this.name + ";" + this.email;
      this.uri = "#" + this.ssid + "&sessionId=" + this.sessiondId + "&ip=" + this.ip + "&mac=" + this.mac + "&ufi=" + this.ufi + "&mgmtBaseUrl=" + this.mgmtBaseUrl + "&clientRedirectUrl=" + this.clientRedirectUrl + "&req=" + this.req + "&username=" + this.userName + "&hmac=" + this.hmac;
      // console.log("LOGAR: " + this.nameFormControl.valid);
      this.document.location.href = this.uri;
    }
    console.log("LOGAR: " + this.nameFormControl.valid);
    console.log("LOGAR: " + this.termsFormControl.valid);
  };

  emailFormControl = new FormControl('', [
    Validators.required,
    Validators.email,
  ]);

  nameFormControl = new FormControl('', [
    Validators.required,
  ]);

  termsFormControl = new FormControl('', [
    Validators.required,
  ]);

}