Vuejs-Datepicker: It shows up but is not working, not clickable or anything else and i dont know why?

Question

Vuejs-Component (btw im using Vuejs2, if its relevant):

import VueDatePicker from '@vuepic/vue-datepicker';
import '@vuepic/vue-datepicker/dist/main.css';
[...]components: {
        VueDatePicker
    },[...]
<VueDatePicker></VueDatePicker>

Main.js:

import VueDatePicker from '@vuepic/vue-datepicker';
import '@vuepic/vue-datepicker/dist/main.css';
window.Vue = Vue;
Vue.createApp(VueDatePicker).mount(document.getElementById("datepicker"));

I tried a lot now, and only one time i could open the frame where you can choose a date. When i was clicking on "Select" nothing was saved, the frame is getting closed and the date wasnt show in the input field. But at this point i did it with the id of the component so in this case with "datepicker". Ty for answering :)