Is it remote connect to the phpBB server stop the forum and install the exporter plugin then start the forum and pick up the entire forum as one database file, then stop new nodeBB forum install plugin then start the new forum and import the file?
it's unclear from what's given.
I also have some perhaps unusual requirements :
I'm not interested in migrating accounts, in fact I specifically do not want to migrate accounts. the migration exists only as comfort for those who want to be able to look up the old archived threads (btw I will mark them all as read-only after migration) but effectively we are starting from scratch with new accounts.
So I'm not interested in migrating the accounts and I'm wondering if that's an issue? do posts necessarily need to be created with an account or is creating posts made by an unattributed user name possible? (if nodeBB attributes posts from the old forum archive to a new forum joinee that's perfectly fine by me, not so if nodeBB refuses that a new joinee use that name under pretext that it's already under use. New users and content must take priority)
will nodeBB allow this or will it require a account named "archivebot" for example to be "responsible", the "author" of all these posts. I'd prefer if I could at least preserve the author names buit if I can't that's an ok sacrifice.
Also will nodeBB allow the original dates for the posts? or will all of them be of the date of the migration?
TLDR: I don't know how to migrate from phpBB 3.0.9 to nodeBB 1.14.2 specifically there doesn't seem to be an upgrade path for those specific version numbers.