Is there a way to I find the Exchange Server Endpoint Address via Thunderbird settings?

using OWAused to be the usual method. Thunderbird has no native support for Exchange. So it will not have the endpoint. The IMAP and POP protocols just don't even have something like the concept. If your using an add-on such as [https://addons.mozilla.org/en-US/thunderbird/addon/exquilla-exchange-web-services/ Exqilla ]then you best check with the add-on author.