Download facebook page messenger history

I manage a Facebook page on which we use Messenger quite a lot to interact with our audience. For other tools I’d like to download transcripts of all conversations over time but I cannot find how.

Both Pages and personal accounts have an option to download the data. For pages it’s called “Download your Page information” under General settings. The only difference is that for pages it is not possible to download your messenger transcripts.

What would be an alternative way to go about this and download the transcripts?