What difference between AdminSiteOTPRequired and OTPAdminSite?

Question

What difference between AdminSiteOTPRequired and OTPAdminSite? couldn't understand at first glance almost identical I use authorization by email, I changed the class in the code to another one, but I didn’t see the difference in the documentation. The only thing I deducted was that one class is specifically for administering admin users, but the second one too?

from two_factor.urls import urlpatterns as tf_urls
from two_factor.admin import AdminSiteOTPRequired
from django_otp.admin import OTPAdminSite
admin.site.__class__ = AdminSiteOTPRequired
urlpatterns = [   
    path('', include(tf_urls)), 
]