Hi @PSM there is a function available in CMS/Content Hub Pro that allows pages to be moved from LPs to Website and vice versa, if you have a pro or enterprise subscription you can access it here:
With Free/Starter this is not an option and you would have to manually add each landing page to the sitemap.
One option would be to enroll in the 14-day trial for content hub pro/enterprise, move your pages over during the trial, and then resume your regular subscription.
There’s a limit to how frequently you can enroll in the trial, so if you’ve already completed a trial you may not be able to again.