Not that I know of, but there is a freeware utility at https://www.nirsoft.net/ that can create an export file of thunderbird passwords. It takes a little tweaking, but works very well. I've used it for years to make backups.

Thanks for that David.

I did look at nirsoft but was concerned that it may contain a trojan virus.

Seems a shame that the facility is not built in (like in Firefox)

Perhaps there is a way of requesting this feature?

Also, the Nirsoft site states:

Mail PassView is a small password-recovery tool that reveals the passwords and other account details for the following email clients: Mozilla Thunderbird (If the password is not encrypted with master password)

I use a master password, so presumably Passview would not work?

Well, you could remove the primary password, do the backup, and then reinstate the primary password.

There is no virus, but you can make suggestions here: https://connect.mozilla.org/t5/ideas/idb-p/ideas/label-name/thunderbird