Fix Error in Header

src/app/header/header.component.html

 <mat-toolbar color="primary">
-
-  <span>Tabu</span>
-  <a href="router.navigate(['/overview'])">
-    <img style="display: inline;" src="./assets/Icon.png" alt="logo" height="30px" width="30"/>
-  </a>
+    <span class="mousefinger" (click)="toStartpage()">Tabu</span>
+    <a>
+      <img class="mousefinger" style="display: inline" src="./assets/Icon.png" alt="logo" height="30px" width="30" (click)="toStartpage()"/>
+    </a>
 </mat-toolbar>

src/app/header/header.component.scss

+.mousefinger {
+  cursor: pointer
+}

src/app/header/header.component.ts

 import { Component, OnInit } from '@angular/core';
+import {Router} from '@angular/router';
 
 @Component({
   selector: 'app-header',
@@ -7,9 +8,12 @@ import { Component, OnInit } from '@angular/core';
 })
 export class HeaderComponent implements OnInit {
 
-  constructor() { }
+  constructor(private router: Router) { }
 
   ngOnInit(): void {
   }
 
+  toStartpage(): void {
+    this.router.navigate(['']);
+  }
 }