Hi,
Browsers have setup web push in a way that ties subscribers to a specific origin (domain/site URL).
For security purposes, browsers do not allow subscribers to be moved to other origins.
Sites with different origins include:
1. Changing from HTTP to HTTPS
2. https://www.mysite.com and non-www version
3. domain1.com and domain2.com
If you changed your site origin, the best solution is to set up a new OneSignal app and have your users subscribe to the new site’s origin under this new OneSignal app.
You will not able to import subscribers from one origin to another origin.
You can continue sending push notifications to your subscribers on the old origin/old OneSignal app, but your users will need to re-subscribe to the new origin to get push from the new domain.
We recommend sending a couple of notifications periodically from the old domain, letting users know that the site has moved and that they should subscribe to the new site URL to stay updated.