adding a button in django admin programmatically

Question

I have a model called "Process" and I want to rename its button in the admin_changelist view. I want to limit the overwriting of templates where possible.

I created a custom form called SingleForm and a form called MultipleForm and I want a button that leads to each form. So I tried the following:

Template first:

{% extends 'admin/change_list.html' %}

{% block object-tools-items %}
    <li>
        <a href="/admin/app/process/add_set/" class="addlink">
            Add multiple Processes
        </a>
    </li>
    {{ block.super }}
{% endblock %}

ModelAdmin:

class ProcessAdmin(admin.ModelAdmin):
    ...

    def get_urls(self):
        urls = super().get_urls()
        my_urls = [path("add_set/", self.add_process_set),]
        return my_urls + urls

    def add_process_set(self, request):
        return MultipleForm

But I only end up with Process with ID “add_set” doesn’t exist. Perhaps it was deleted?

Bonus question: How can I ONLY show the the button for add_set and omit the normal add button (I'd prefer without overwriting the template)?