When you are HTTPS and you sign up for Subscribers you’ll be using the Browser Native Opt-in option which looks like this:
The browsers have complete control over what is shown in this opt-in so unfortunately, we are not able to change the text in the buttons or alert.
But there is a silver lining to this. The browsers are starting to standardize the look and feel of web push notifications and this will make them more trusted by the average person. The more your visitors trust your site, the more subscribers you should receive.
Note: Subscribers is currently adding support for Firefox and Chrome on Android. Subscribers does not currently support Opera, iOS, or Edge.