Drupal 8 doesn't display Rocket Chat

Hi all, I installed Rocket Chat in Drupal 8.9.8, correctly configured the module and placed the blocks, but the chat does not appear. The browser gives me the following message: "This page cannot be opened in Firefox

To protect your safety, euchat2.rocket.chat does not allow Firefox to display the page when it is included within another site. To view this page you need to open it in a new window. ".
Also on the screen, in correspondence to the regions of the blocks, the following message appears: “Channel not available., Contact the site admin.” And “Unable to locate channel, Contact the administrator”
In Firefox this is the screenshot:
Schermata 2020-11-09 alle 14.15.18
)Connection refused by eumanschat.rocket.chat

How can I solve this problem? Thanks in advance! :slight_smile: