Try clicking your profile icon at the top right then clicking "My Settings", you should immediately see an input field to change your user name
If you don't see an option to do that in Settings, try contacting @MaddieJ about it!
Here's a thread where someone else faced a similar issue: https://community.airtable.com/t5/other-questions/how-do-i-change-my-community-display-name/td-p/188...
