s2forms.Select2Widget no results in template

[fxlxx]

Goal
Don't use a Django Model but a SQL query or dummy data

Problem
No results are shown in template, it's just an empty dropdown menu

Code Snippet

from django import forms
from django_select2 import forms as s2forms

class UserWidget(s2forms.Select2Widget):

    def build_attrs(self, *args, **kwargs):
        attrs = super().build_attrs(*args, **kwargs)

        # some dummy data which will be replaced by an sql query
        data = [
            {'id': '1', 'text': 'Example1'},
            {'id': '2', 'text': 'Example2'},
            {'id': '3', 'text': 'Example3'},
            {'id': '4', 'text': 'Example4'},
        ]
        attrs['data'] = data

        return attrs



class UserForm(forms.Form):
    user = forms.ChoiceField(widget=UserWidget)

What am i missing? A ModelSelect2Widget works fine, so the probem should be in my forms.py