You can try this

<script setup>
import { useEditor, EditorContent } from '@tiptap/vue-3'
import StarterKit from '@tiptap/starter-kit'
import { onBeforeUnmount, watchEffect } from 'vue';

const props = defineProps({
    modelValue: {
        type: String,
        default: ''
    }
});

const emits = defineEmits(['update:modelValue'])

watchEffect(() => props.modelValue, (newValue, oldValue) => {
    const isSame = newValue === oldValue;
    if (isSame) {
        return;
    }

    editor.value?.commands.setContent(newValue, false)
});

const editor = useEditor({
    content: props.modelValue,
    extensions: [
        StarterKit,
    ],
    onUpdate: ({ editor }) => {
        let content = editor.getHTML()
        emits('update:modelValue', content)
    },
});

onBeforeUnmount(() => {
    editor.destroy();
})

</script>