Hi Amanda,
My name is Didi, an Independent Advisor.
If your work account requires a PIN when you sign in it may indicate that they enabled multi-factor authentication in your organization. It's usually related to the device you're using. If you have some issues, you could contact your IT admin to reset or try the instruction on this link:
https://docs.microsoft.com/en-us/windows/securi...
For the meeting chat, could you check the meeting options to see if chat is enabled? Please read 'Allow meeting chat' on this article:
https://support.microsoft.com/en-us/office/chan...
Thank you.