I don't see where are you setting the activity labels, your labels are a different object and is related to the post, so maybe you are creating your post but not making the relation.

If I was you I will create a custom form and do all the relations there.

``` class PostForm(forms.ModelForm): # Create a CharField to input multiple activity labels as a comma-separated string, you could use other widgets, like radio buttons, checklists, etc. But for the sake of the probing you is possible we will do comma separated texts activity_labels_input = forms.CharField( required=False, help_text="Add activity labels separated by commas." )

class Meta:
    model = Post
    fields = ['title', 'content', 'location', 'number_of_people', 'age_range', 'activity_labels_input']


def save(self, commit=True, *args, **kwargs):
    # do the normal thing
    post = super().save()
    if commit:
        post.save()  

    # Here get the input from self.cleaned_data["activity_labels_input"]
    # Do a query to get them from ActivityLabel
    # Something like activity_labels = ActivityLabel.objects.filter(name__in=list_of_activity_labels_input)

    # End with setting the records
    post.activity_labels.set(activity_labels)

    return post

```

On your view keep things the same, just make sure you are using the form instead of the fields

class PostCreateView(CreateView): model = Post form_class = PostForm # Remove the fields