fixing phone number bug

authentication/migrations/0003_auto_20210629_2034.py

+# Generated by Django 3.1 on 2021-06-29 13:34
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('authentication', '0002_auto_20210601_1536'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='customuser',
+            name='deadline',
+            field=models.DateField(blank=True, null=True),
+        ),
+    ]

authentication/serializers.py

@@ -76,7 +76,7 @@ class CustomUserDetailsSerializer(serializers.ModelSerializer):
         if onboarding_status['is_finished_onboarding'] is True\
             and 'role' in onboarding_status:
             phone_number = instance.diet_questionnaire.whatsapp_no
-            if phone_number is None:
+            if (phone_number is None) or (phone_number == ""):
                 phone_number = instance.diet_questionnaire.handphone_no
             result['phone_number'] = phone_number
         return result