How to implement a multi-step form in Django admin

My task is to give the opportunity to fill out the form in several steps, processing the result of each step.

I found an example of what I need, but this example of 2009

I know about wizard form, but I do not understand how to implement it in Dango admin.

I tried to do this:

def get_urls(self):
    urls = super(MyCustomAdmin, self).get_urls()
    my_urls = [
        url(r'^my_view/$', Wizard.as_view([Form1, Form2]))        
    ]
    return my_urls + urls

But got an error:

AttributeError at /admin/сustom/custommodel/my_view/

'NoneType' object has no attribute 'rsplit'

Perhaps Wizard form are not the best option. But I do not know how to implement the task set otherwise