1, Bai Sirui is a network language, which originated from the transliteration of English sorrybye, but the order of words changed a little after transliteration, so as not to make others feel too embarrassed and maintain basic social politeness. Usually used when they don't want to continue chatting with each other, which is equivalent to words like hehe, haha, oh, etc.
2. To sum up, Bai Sirui is a kind of net language that doesn't want to continue chatting. Generally, it is used when you are busy or don't want to keep in touch with each other, so you should be more interested and don't pester yourself.