Import user and trigger password inline hook during account migration

Hello team,
Is there a way to trigger and inline hook for a user login event when the userID doesnt exist in Okta ?
While migrating accounts from a external data source to Okta, we do a bulk import and set the account to trigger password inline hook to validate and set password. But, there could be a chance that a user maynot be imported before they try to authenticate against okta.
Wondering if an inline hook can be triggered for a userID which doesnt exist in Okta, so that we can handle importing of the account and password in one go.
Any workarounds for this usecase ?

Thanks all !
Trying to figure out a

The only way to trigger the password inline hook is to import the user into Okta and then wait for the user to attempt to login.

Maybe you could take a look at using Event Hooks (which is async, instead of sync like inline hooks) to track failed authentications (will fall under user.session.start event type) and have your endpoint check whether or not the user needed to be imported but has not yet.

This might not scale terribly well since the event hook would be triggered for any login event, but its the only option I can really think of.