this.$inertia undefined in vue typescript component

[Sairahcaz]

Hello,

I have a clean Inertia+Vue3 steup.
Now I want to use TypeScript also.
I installed the ts-loader and typescript.
My app.ts file gets compiled properly and I can use typescript syntax.
But now if I change my vue-component to typescript it seams this.$inertia is undefined.

<script lang="ts">
import { defineComponent } from "vue";
import AppHeader from "@/Layouts/AppHeader.vue";

export default defineComponent({
    components: {
        AppHeader,
    },
    data() {
        return {
            form: this.$inertia.form({
                name: "",
            }),
        };
    },
    methods: {
        store() {
            this.form.post(route("tests.store"), {
                preserveScroll: true,
            });
        },
    },
});
</script>