When i make property as id!:string; or id:string=''; when i assign the value of params i get an error

(property) MoreParametersComponent.id: string ts(2322)Type 'string | null' is not assignable to type 'string'. Type 'null' is not assignable to type 'string'.

import { Component, OnInit } from '@angular/core';
import { ActivatedRoute } from '@angular/router';

@Component({
  selector: 'app-more-parameters',
  templateUrl: './more-parameters.component.html',
  styleUrls: ['./more-parameters.component.css']
})
export class MoreParametersComponent implements OnInit {
  id!: string; // or id:string='';
  id2:number=0;
  constructor(private activatedRoute:ActivatedRoute) { }

  ngOnInit(): void {
    this.activatedRoute.paramMap.subscribe(params=>{
      this.id=params.get('id'); // gives the above error here
      this.id2=parseInt(params.get('id2'));//error
    });
  }

}

How do I get around this error?

My Rest of the Code:

app.component.html

<a routerLink=""> Home </a><br>
<a routerLink="one-parameter,'p01'"> One-Parameter </a><br>
<a routerLink="more-parameter,{id:'p02',id2:123}"> More-Parameter </a> 
<br><br>
<router-outlet></router-outlet>
<br><br>

Route.config.ts

import { Routes } from '@angular/router'
import { HomeComponent } from './home/home.component';
import { MoreParametersComponent } from './more-parameters/more-parameters.component';
import { OneParamterComponent } from './one-paramter/one-paramter.component';


export const mainroute:Routes=[
    {path:'',component:HomeComponent},
    {path:'one-parameter',component:OneParamterComponent},
    {path:'more-parameter',component:MoreParametersComponent}
];