Q. Why don't I see the citation style I need in EndNote Web?

If you are only seeing 21 styles in the EndNote Web account under Bibliography, then your roaming access is not set up or has expired.

To activate/re-activate your roaming access, log into EndNote Web from an IP-Authenticated computer. This can be your laptop connected to the ECwifi network, or a campus PC. This will add roaming/off-campus access for 12 months. To check the expiry, go to Options in the EndNote web and choose Subscription. Once the roaming is activated, you should be able to see all the styles available in your Bibliography list.

For more information about the roaming feature, you can check out this Knowledge Base article from Clarivate: https://support.clarivate.com/ScientificandAcademicResearch/s/article/Web-of-Science-AnytimeAnywhere-Access-or-Roaming?language=en_US.