How to add a custom text to a field (translatable) label - extjs

Question

I have an object with a localizedfields data:
I want to customize the Backend UI for my DataObject, because it's not possible, that field(-s) is required only for one language.
I know, how can I check the mandatories in PHP Event Listener, but I can not find any info, how can I add an asterisk to a field label only for German language.
Here is my JS:
pimcore.registerNS('pimcore.test.plugin');
pimcore.test.plugin = Class.create(pimcore.plugin.admin, {
getClassName: function () {
return 'pimcore.test.plugin';
},
pimcoreReady: function (params,broker) {
},
initialize: function () {
pimcore.plugin.broker.registerPlugin(this);
},
postOpenObject: function (object, type) {
if (object.data.general.o_className === 'Product') {
// add an asterisk to field label
}
},
});
let PimcoreTestPlugin = new pimcore.test.plugin();
Update 1: I have found in Pimcore Sources the part, that adds an asterisk to any field, if field is required, but how can I extend / override them?
pimcore.registerNS("pimcore.object.helpers.edit");
pimcore.object.helpers.edit = {
getRecursiveLayout: function (l, noteditable, context, skipLayoutChildren, onlyLayoutChildren, dataProvider, disableLazyRendering) {
...
// add asterisk to mandatory field
l.titleOriginal = l.title;
if(l.mandatory) {
l.title += ' <span style="color:red;">*</span>';
}
...
}
};

Answer 1

I do not know how to do it with PimCore, but the solution would be to use data-binding:
In Modern
items: [{
xtype: 'textfield',
fieldLabel: 'Name',
bind: {required: '{isGerman}'}
}]
In Classic
Ext.define('MyApp.overrides.form.field.Text', {
override: 'Ext.form.field.Text',
config: {
allowBlank: true
}
});
...
items: [{
xtype: 'textfield',
fieldLabel: 'Name',
bind: {allowBlank: '{!isGerman}'}
}]
if allowBlank|required are will add the asterix.
required will add the asterix if true. allow
Blank will add the asterix if false.

Answer 2

You can create a custom data type, where you specify the languages that are allowed to be edited / where it should be shown. In Pimcore this is done via CoreExtensions on the backend side and a custom data tag in JS.
https://pimcore.com/docs/pimcore/current/Development_Documentation/Extending_Pimcore/Bundle_Developers_Guide/Adding_Object_Datatypes.html