I sent a text message to a female classmate asking me if I would go to study in the evening. As a result, I sent it at 9 am, and she didn't reply until 2 pm now.

You can send text messages next time. The text message reads as follows: Some, I didn't reply to the message last time I asked you to study by yourself, which led me to stare at my mobile phone for half an hour. Are you free this time? Let's study by ourselves, or I'll watch my mobile phone for half an hour if you reply a message. What time is it at night? I'll wait at a table, haha.

The first time, people don't know how to refuse you. They are struggling whether to study with you or not, and finally choose not to reply to the message. So when they wait for the second time, they make the content funny and pretend it's okay, otherwise people will mind.