There is a couple of ways to transfer your content to another bot. You can copy each flow separately or transfer your whole bot to any other account you manage. And here's how.
Bot Cloning feature allows you to transfer the content to your any other account with just a couple of clicks. It will copy all your flows and automations (except Growth Tools) to the destination account, but keep in mind that if your source account is Pro, your destination account should also be Pro to perform the cloning.
To clone your bot, go to Settings -> General and click Clone This Bot button.
Then select one of the accounts you manage in a drop-down menu. Once you do that, your destination account'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 account. Now you can go to your new bot or stay in the current one.
Let's go to our destination account and find transferred content there to make sure everything was copied fine. As you can see, new folder with source account 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.
If while trying to clone the bot to another account you got this or any other error, it's most likely that there's some corrupted content in your source account. A quick way to find them yourself is to create a Template with all the content from this account.
The Template will highlight all corrupted elements in red, so you will be able to quickly find and fix them. The issue is usually caused by unpublished or deleted Flows on the source bot.