I have an embedded login app set up to allow customers to use their Community Credentials to log in to an externally hosted website. The user is able to log in successfully (as shown with Login History in Salesforce) however the embedded login just sits there with a greyed out Log In button.
Even if a put a simple alert in to display onLogin, nothing shows.
What am I missing? How do I tell the embedded login what to do after login because right now it seems like it just doesn't know what to do and just sits.
I am happy to see your post as I am facing the exact problem. The login button is getting greyed out and I am not able to call the "onLogin" javascript function. <meta name="salesforce-login-handler" content="onLogin"> I can also see the successfull login logs in Salesforce but in the external heroku app I am unable to call the onLogin function. Could you please share how you fixed that problem?