There is a couple of ways to transfer your content to another page. You can copy each flow separately or transfer your whole bot to any other page you manage. And here's how.
Bot Cloning feature allows you to transfer the content to your any other page with just a couple of clicks. It will copy all your flows and automations (except Growth Tools) to the destination page, but keep in mind that if your source page is Pro, your destination page should also be Pro to perform the cloning.
To clone your bot, go to Settings and click Clone This Bot button.
Then select one of the pages you manage in a drop-down menu. Once you do that, your destination page's Welcome Message, Default Reply and conflicting Keywords will get new flows attached (still, you can find your old flows in Flows Section and use them again).
As soon as you click Clone button, the system will return a note:
After you clone the content of the source bot to the receiving one, you won’t be able to easily uninstall this content. You can still delete everything manually if you wish. Besides, all of Messenger Flows of the receiving bot will remain, so no truly irreversible changes are done.
Click Clone Now to proceed. You will receive Cloning Successful! message that means your content was transferred to the receiving page. Now you can go to your new bot or stay on the current page.
Let's go to our destination page and find transferred content there to make sure everything was copied fine. As you can see, new folder with source page name was created in Flows Section and all my cloned flows are stored inside so I could easily find and manage them.
Since now my Welcome Message, Default Reply and conflicting Keywords have new flows attached. All my old flows were detached and they're still accessible in Flows Section so I can use them again in case I change my mind.