Sometimes when you work with onesignal push notifications you may have an error : 

there is an error :
ConfigHelper.js:52 Uncaught (in promise) f: OneSignal: This web push config can only be used on Your current origin is

Change the web configuration page URL to :

And add below code to your .htaccess file :

RewriteEngine On
RewriteCond %{HTTP_HOST} ^
RewriteRule (.*)$1 [R=301,L]

After changes, go to plugin again and click to save the plugin.