Use filter in Vue3 but can't read globalProperties - vue.js

Question

Just a quick question,
I know that Vue3 doesn't use filters anymore and notes says use computed or methd instead. but also there is a globalProperties we can use,
I used this globalProperties but keep getting this error
Uncaught TypeError: Cannot read property 'globalProperties' of undefined
Does anyone know where is the bug in my code?
const app = {
data() {
return {
message: ""
}
}
}
app.config.globalProperties.$filters = {
formatDate(value) {
if (value == "0001-01-01T00:00:00")
return "";
var today = new Date(value);
var dd = String(today.getDate()).padStart(2, '0');
var mm = String(today.getMonth() + 1).padStart(2, '0'); //January is 0!
var yyyy = today.getFullYear();
today = dd + '/' + mm + '/' + yyyy;
return today;
}
}
Vue.createApp(app).mount('#app');
And I am using the filter in my table like this
<td>
{{ $filters.formatDate(incident.incidentData) }}
</td>

Answer 1

The config field belongs to the root instance not to the root component so you should do:
const app = {
data() {
return {
message: ""
}
}
}
const myApp=Vue.createApp(app)
myApp.config.globalProperties.$filters = {
formatDate(value) {
if (value == "0001-01-01T00:00:00")
return "";
var today = new Date(value);
var dd = String(today.getDate()).padStart(2, '0');
var mm = String(today.getMonth() + 1).padStart(2, '0'); //January is 0!
var yyyy = today.getFullYear();
today = dd + '/' + mm + '/' + yyyy;
return today;
}
}
myApp.mount('#app');
Vue.createApp(app) return the root instance
myApp.mount('#app'); after mounting root app to an element it returns the root component