Where I am doing wrong? Form is not fetching data from server

my form.py

from app.models import CredentialModels

class EmailForm(forms.Form):
    email = forms.ChoiceField(choices=[], widget=forms.Select(attrs={'class': 'form-control'}))
    signature = forms.CharField(widget=forms.Textarea(attrs={'class': 'form-control', 'rows': 5}))

    def __init__(self, user_id, *args, **kwargs):
        super().__init__(*args, **kwargs)
        credentials = CredentialModels.objects.filter(user_id=user_id)
        self.fields['email'].choices = [(c.email, c.email) for c in credentials]

My views.py:

def update_signature(request):
     email_form = EmailForm(user_id=request.user.id)
    return render(request, 'update_signature.html', {'email_form': email_form})

My model:

class CredentialModels(models.Model):
    user_id = models.CharField(max_length=255)
    email = models.EmailField()
    access_token = models.CharField(max_length=255)
    token_expiry = models.DateTimeField()
    refresh_token = models.CharField(max_length=255)
    client_id = models.CharField(max_length=255)
    client_secret= models.CharField(max_length=255)
    def __str__(self):
        return self.email
    class Meta:
        verbose_name_plural = "Email"

And form:

{% block content %}
  <div class="row">
    <div class="col-md-6 offset-md-3">
      <form method="get">
        {% csrf_token %}
        <div class="form-group">
          {{ email_form.email.label_tag }}
          {{ email_form.email }}
        <div class="form-group">
          {{ email_form.signature.label_tag }}
          {{ email_form.signature }}
        <button type="submit" class="btn btn-primary">Update</button>
{% endblock %}

I want to see the email of the current loggedin user on form select. But it shows empty dropdownlist

The field request.user.id is going to be an integer value.

However, in your CredentialModels you have:

If CredentialModels is supposed to be associated with a specific user, then the user_id field should probably be either a ForeignKey or OneToOneField with User, and more appropriately named user instead of user_id.