15654 check for no termination in TunnelTerminationSerializer

netbox/vpn/api/serializers.py

@@ -98,6 +98,9 @@ class TunnelTerminationSerializer(NetBoxModelSerializer):
 
     @extend_schema_field(serializers.JSONField(allow_null=True))
     def get_termination(self, obj):
+        if not obj.termination:
+            return None
+
         serializer = get_serializer_for_model(obj.termination, prefix=NESTED_SERIALIZER_PREFIX)
         context = {'request': self.context['request']}
         return serializer(obj.termination, context=context).data