Does the subject want to ask, "Why does the connection fail when singing?" Network problems. The connection of singing, code scanning and song ordering failed. Need to check whether there are network problems such as arrears and downtime in the mobile phone. If there is arrears, it cannot be used normally. After charging, it can be used normally. Sing it app is a fashionable mobile phone KTV, where hundreds of millions of users get together to make friends and beautify the sound with one click.