When a girl is angry, she should think about what she said wrong and make the other party angry. Only in this way can she prescribe the right medicine to the case and apologize better. Especially, the other party will definitely ask where the wrong is, so she must think about what she said wrong.
If you really don't know what you said wrong, you can hint to ask the girl to point out your mistake. For example, "I made a mistake today. I didn't speak with my head. I forgot what I said at once. If someone is willing to point out to me, it would be great". At this time, if the girl is willing to answer you, she will tell you your mistake.
If a girl doesn't want to answer you or say what you said wrong, that is, she is angry, then you should be careful to please her, buy something she likes, such as lipstick bags, or tell jokes to amuse her, so that she won't be angry, but in addition to giving gifts, you should also see the opportunity to apologize.