Username of phone oppo f1s

There are no 'user names' for a phone. There is a manufacturer's name. There is also the model name, but any 'user name' would belong to the person who owns the phone. The name they assigned to the account that is being accessed. Phone's don't have user names.

We wouldn't have such information, only the owner would, so if the phone is yours your should know the name to whatever you are trying to access. If the phone isn't yours, then I suggest you return it.