Bubble OneSignal Plugin Not subscribing after clicking on "subscribe"

Hi,

I followed the bubble manual to set up onesignal, but I am running into the following window when I hit “subscribe” on the notification prompt. The process seems to stop with this blank window and does not follow through to complete the “subscribe” action.

Wondering if anyone knows what might have caused this? It’s happening across browsers for me. Thanks a million!

Max