Cannot generate interface documentation for viewsets specific interface when “”versioning_class = NamespaceVersioning” is added to view

[Cloverxue]

Describe the bug
Cannot generate interface documentation for viewsets specific interface when “”versioning_class = NamespaceVersioning” is added to view
The interface document for MyViewSet disappears when adding “versioning_class = NamespaceVersioning” to MyViewSet，
for example:
from rest_framework.versioning import NamespaceVersioning
class MyViewSet(mixins.ListModelMixin, viewsets.GenericViewSet):
versioning_class = NamespaceVersioning

To Reproduce
A:
class MyViewSet(mixins.ListModelMixin, viewsets.GenericViewSet):
pass
B:
class MyViewSet(mixins.ListModelMixin, viewsets.GenericViewSet):
versioning_class = NamespaceVersioning
A can generate interface documents normally, but B cannot

Expected behavior
Expect normal interface documentation to be generated

[Cloverxue]

url('^api-ui/', SpectacularSwaggerView.as_view(url_name='schema'), name='swagger-ui'),
url('^api-doc/', SpectacularRedocView.as_view(url_name='schema'), name='swagger-doc'),
The corresponding interface(versioning_class = NamespaceVersioning) cannot be found when opened using this two url

[tfranzel]

https://drf-spectacular.readthedocs.io/en/latest/faq.html#i-get-an-empty-schema-or-endpoints-are-missing

you can do hardcode which version (as explained above) or give a parameter ...../api-ui/?version=v1

there is also the possibility for a dropdown in SwaggerUI: #1036 (comment)

[Cloverxue]

Hi ,./manage.py spectacular --api-version 'YOUR_VERSION' can generate interface documents normally, but
url('^api-ui/', SpectacularSwaggerView.as_view(url_name='schema'), name='swagger-ui'),
url('^api-doc/', SpectacularRedocView.as_view(url_name='schema'), name='swagger-doc'),
The corresponding interface(versioning_class = NamespaceVersioning) cannot be found when opened using this two url

[Cloverxue]

Ok, it's fine, thank you very much!