I managed to do it using these examples:
But there should be examples in Svelte native :/ The Svelte Native implementation was way better since you didn't even need to import anything: https://svelte-native.technology/docs#bottom-navigation. They should keep it! :( Also, docs were centralized and now that they deprecated their implementation you need to try to find examples that most times do not exist :/
<script>
import { registerNativeViewElement } from "svelte-native/dom";
import {
BottomNavigation,
TabStrip,
TabStripItem,
TabContentItem,
} from "@nativescript-community/ui-material-bottom-navigation";
registerNativeViewElement("bottomNavigation", () => BottomNavigation);
registerNativeViewElement("tabStrip", () => TabStrip);
registerNativeViewElement("tabStripItem", () => TabStripItem);
registerNativeViewElement("tabContentItem", () => TabContentItem);
</script>
<page>
<bottomNavigation selectedIndex="1">
<!-- The bottom tab UI is created via TabStrip (the containier) and TabStripItem (for each tab)-->
<tabStrip backgroundColor="#C8F7C5">
<tabStripItem>
<label text="Home"></label>
<image src="font://" class="fas"></image>
</tabStripItem>
<tabStripItem class="special">
<label text="Account"></label>
<image src="font://" class="fas"></image>
</tabStripItem>
<tabStripItem class="special">
<label text="Search"></label>
<image src="font://" class="fas"></image>
</tabStripItem>
</tabStrip>
<!-- The number of TabContentItem components should corespond to the number of TabStripItem components -->
<tabContentItem>
<gridLayout>
<label text="Home Page" class="h2 text-center"></label>
</gridLayout>
</tabContentItem>
<tabContentItem>
<gridLayout>
<label text="Account Page" class="h2 text-center"></label>
</gridLayout>
</tabContentItem>
<tabContentItem>
<gridLayout>
<label text="Search Page" class="h2 text-center"></label>
</gridLayout>
</tabContentItem>
</bottomNavigation>
</page>