Hide the determination button if user cant use it

opentech/apply/determinations/templates/determinations/includes/determination_button.html

 {% load determination_tags workflow_tags %}
-{% if request.user|can_add_determination:submission %}
+{% if request.user|show_determination_button:submission %}
     <a href="{% url 'apply:submissions:determinations:form' submission_pk=submission.id %}" class="button button--primary button--full-width">
         {% if submission.determination.is_draft %}Update draft{% else %}Add determination{% endif %}
     </a>

opentech/apply/determinations/templatetags/determination_tags.py

 from django import template
+from django.db.models import ObjectDoesNotExist
 
-from ..views import can_create_determination
+from ..views import can_create_determination, can_edit_determination
 
 register = template.Library()
 
 
 @register.filter
-def can_add_determination(user, submission):
-    return can_create_determination(user, submission)
+def show_determination_button(user, submission):
+    try:
+        return can_edit_determination(user, submission.determination, submission)
+    except ObjectDoesNotExist:
+        return can_create_determination(user, submission)