"No [MyTask] tasks found" is displayed after setting the task provider (VSCode Extension Dev)

I looked at various sites and created the minimum required TaskProvider code. However, I get the message "task not found" and can't get it to work. Am I missing something that I need?

enter image description here

Environment:
  VSCode: latest as of 2/20/2021
  OS: Windows 10 (latest update)

package.json

  "contributes": {
    "taskDefinitions": [
      {
        "type": "mytask"
      }
    ]

extension.ts

import * as vscode from 'vscode';
import { MyTaskProvider } from './myTaskProvider';


let myTaskProvider: vscode.Disposable | undefined;


export function activate(context: vscode.ExtensionContext) {
    myTaskProvider = vscode.tasks.registerTaskProvider(
        MyTaskProvider.TASK_TYPE, new MyTaskProvider()
    );
}

export function deactivate() {
    if (myTaskProvider) {
        myTaskProvider.dispose();
    }
}

myTaskProvider.ts

import * as vscode from 'vscode';


export class MyTaskProvider implements vscode.TaskProvider {
    static TASK_TYPE = 'mytask';

    public provideTasks(): Thenable<vscode.Task[]> | undefined {
        return _generateTasks();
    }

    public resolveTask(_task: vscode.Task): vscode.Task | undefined {
        const definition = _task.definition;
        return _createTask(definition)
    }
}

function _createTask(definition: vscode.TaskDefinition) {
    return new vscode.Task(
        definition,
        vscode.TaskScope.Workspace,
        "my task name",
        definition.type,
        new vscode.ShellExecution("echo \"Hello!\"")
    );
}

async function _generateTasks(): Promise<vscode.Task[]> {
    const taskList: vscode.Task[] = [
        _createTask({type: MyTaskProvider.TASK_TYPE})
    ];
    return taskList
}

This code mimics the way vscode-sample is written in some parts. If you run this code, you will not get any errors, but you will also not get any information about the list of tasks.

Do you have any ideas?