I guess vue-cli doesn't have component creator command yet. You can use vue-generate-component

Below is a simplistic solution that works (I'm not an expert in Vue 3).

The main point is to use addRoute before pushing to it, because you cannot specify the route component when pushing to a route.

Here is the codesandbox with the working solution.

 <template>
  <router-link to="/">Home</router-link>
  <button @click="createComponent">Create Component</button>

  <router-view></router-view>
</template>

<script>
import { getCurrentInstance } from "vue";
import { useRouter } from "vue-router";
export default {
  name: "App",
  setup() {
    const app = getCurrentInstance().appContext.app;
    const router = useRouter();

    const createComponent = () => {
      // Check if the component has been alreadey registered
      if (!app.component("NewComponent")) {
        app.component("NewComponent", {
          name: "NewComponent",
          template: `<div>This is a new component</div>`
        });
      }

      const newComponent = app.component("NewComponent");
      // Adding a new route to the new component
      router.addRoute({ path: "/new", component: newComponent });

      router.push("/new");
    };
    return {
      createComponent,
    };
  },
};
</script>