forms.py

from django import forms
from .models import Customer, Request

class CreateRequestForm(forms.ModelForm):
  customer = forms.CharField()    
  
  def clean(self):              # update
        data = self.cleaned_data.pop('customer')
        customer, created = Customer.objects.get_or_create(name=data)
        self.cleaned_data.update({'customer': customer})
 
  class Meta:
        model = Request
        fields = '__all__'