Python API SSL error

I’m trying to test the NC python api. I create an nxc object but when I issue nxc .get_users(), I get an SSL error. I am running NC 18

  File "<string>", line 1, in <module>
  File "/private/var/mobile/Containers/Shared/AppGroup/05D14C00-CCAC-4E98-A3CC-96C6944B8534/Pythonista3/Documents/site-packages-3/nextcloud/api_wrappers/user.py", line 34, in get_users
    return self.requester.get(params=params)
  File "/private/var/mobile/Containers/Shared/AppGroup/05D14C00-CCAC-4E98-A3CC-96C6944B8534/Pythonista3/Documents/site-packages-3/nextcloud/requester.py", line 19, in wrapper
    getattr(e.request, 'url', None), e)
nextcloud.requester.NextCloudConnectionError: ('Failed to establish connection to NextCloud', 'https://nextcloud.url/ocs/v1.php/cloud/users?format=json', SSLError(MaxRetryError("HTTPSConnectionPool(host='Nextcloud.url', port=80): Max retries exceeded with url: /ocs/v1.php/cloud/users?format=json (Caused by SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749)'),))",),)) `
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/private/var/mobile/Containers/Shared/AppGroup/05D14C00-CCAC-4E98-A3CC-96C6944B8534/Pythonista3/Documents/site-packages-3/nextcloud/api_wrappers/user.py", line 34, in get_users
    return self.requester.get(params=params)
  File "/private/var/mobile/Containers/Shared/AppGroup/05D14C00-CCAC-4E98-A3CC-96C6944B8534/Pythonista3/Documents/site-packages-3/nextcloud/requester.py", line 19, in wrapper
    getattr(e.request, 'url', None), e)
nextcloud.requester.NextCloudConnectionError: ('Failed to establish connection to NextCloud', 'https://nextcloud.url/ocs/v1.php/cloud/users?format=json', SSLError(MaxRetryError("HTTPSConnectionPool(host='nextcloud.url', port=80): Max retries exceeded with url: /ocs/v1.php/cloud/users?format=json (Caused by SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749)'),))",),))

You use https://github.com/owncloud/pyocclient?

Did you check your SSL setup?
https://www.ssllabs.com/ssltest/