There are a number of reasons why you may not be able to see the EndNote Cite while Your Write tools in Word. The troubleshooting guide which is available at: https://support.clarivate.com/Endnote/s/article/EndNote-X8-Mac-and-EndNote-online-Mac-CWYW-tools-in-Microsoft-Word-2016-Troubleshooting-guide?language=en_US covers the following issues

• After installing the tools the EndNote tab is still missing in Word
• Missing or phantom tab in Word
• Tools are present but not responsive
• Tools are missing but everything appears correctly configured

The instructions are for Word 2016, 2019 and 365.