If you are looking to use it for xenForo : https://theadminzone.com/resources/...h-notifications-now-with-simple-install.1069/ But if you want to use it for any website, you need to read and follow the instruction in theirwebsite.
@Sidradi I saw but they reject me or They don't accept new member I dont know. I haven't downloaded this resource yet. Maybe you can help me ... Again thanks. Hi friend, Who can help me about this question? I'm sorry This message is not flood.
That the only placefrom you can download a custom extension for xenForo. Otherwise you need to follow the instruction here : https://documentation.onesignal.com/docs to add it to your website, community, blog etc...