How to connect vuelidate?

Question

Vue.js

I'm learning vue 3 (before that I didn't work with vue at all). I took up vuelidate. I watch the vid. They say that the $v object should appear in vue dev tools.
Does not appear.

I connect vuelidate not through cli, but like this:

<script src="Vue.js"></script>
<script src="vuelidate.min.js"></script>
<script src="validators.min.js"></script>
<script src="app.js"></script>

js:

import useVuelidate from '@vuelidate/core' // пишет 'Cannot use import statement outside a module'

Vue.use(window.vuelidate.default) // пишет 'Vue.use is not a function'

If I do this: then it appears in vue dev tools I'm confused.

Vue.createApp(Submit, vuelidate).mount('.main')