Hi.
Please read this https://support.box.com/hc/en-us/articles/360043696414-WebDAV-with-Box
Disclaimer: I am not using box.com and thus cant try it. maybe an other user managed to get a connection, but from my point of view it seems like box.com does not have interest in providing a reliable WebDAV connection
For me important notes:
Note: Web browser access is not supported. You must use a WebDAV client.
As of October 25, 2019, Box has ended WebDAV support. If you have been using WebDAV you can continue to use it, as described in this article below. But we are no longer resolving any issues that may arise as a result.
[Jan 2022] TOTP-based Multi Factor Authentication (with Authenticator App) is not supported with WebDAV. Chose SMS-based Multi Factor Authentication instead.