How to gracefully send a circle of friends, saying that children can't talk on the phone for the time being.

Take a photo of the child taking an online class, and match it with the relevant copy:

You want to find my friends. Because the child is taking an online class with my mobile phone, I can't answer the phone. You can leave a message if you have something. I'm sorry if you see it.

Other elegant ways to make friends:

Share your life feelings; Self-portrait photos should be available, but not too many. Sending self-portraits every day will only make you look narcissistic. After all, a person's connotation is the lasting charm. Usually, you can write a little about your own feelings about life and share your own views.