Messenger on desktop

Hi! I have just installed the free version.
I’ve selected facebook messenger but it’s not working on the desktop. It appears a blank page, but with the mobile link works just fine.

I’ve also tried by clicking on the messenger button on this page https://premio.io/help/chaty/, but it happens the same, opens a blank page.

I already check if my Facebook page is available for all countries. Is there another possible way to solve this?
Thanks!!

The page I need help with: [log in to see the link]