I’m trying to develop a VSCode extension, but the compilation doesn’t finish, and I can’t open the Extension Development Host window

I’m trying to develop a VSCode extension, but the compilation doesn’t finish, and I can’t open the Extension Development Host window.

.vscode/tasks.json

{
    "version": "2.0.0",
    "tasks": [
        {
            "type": "npm",
            "script": "watch",
            "problemMatcher": [
                "$ts-webpack-watch",
                "$tsc-watch"
            ],
            "isBackground": true,
            "presentation": {
                "reveal": "never",
                "group": "watchers"
            },
            "group": {
                "kind": "build",
                "isDefault": true
            },
            "runOptions": {
                "runOn": "folderOpen"
            }
        },
        {
            "type": "npm",
            "script": "watch-tests",
            "problemMatcher": "$tsc-watch",
            "isBackground": true,
            "presentation": {
                "reveal": "never",
                "group": "watchers"
            },
            "group": "build"
        },
        {
            "label": "tasks: watch-tests",
            "dependsOn": [
                "npm: watch",
                "npm: watch-tests"
            ],
            "problemMatcher": []
        }
    ]
}

I am stuck on this screen.

I tried to run it using the F5 key. I expected the Extension Development Host window to appear, but it seems that the window does not show up because the compilation is not finished.