Can I send text messages while using 4G?

You can send text messages while using 4G.

Short message service (English: Short message service, abbreviated as SMS) is called SMS in Mainland China, SMS in Hong Kong, and SMS in Taiwan. It is a type of mobile phone service that users can send or receive directly through mobile phones or other telecommunications terminals. text or numeric information, translated from the English "Short Message Service". Available on most mobile phones. Sometimes also called messages, short messages, text messages, text messages, this service also has many common English names such as "SMSes, Text messages, messages or even texts and txts". The SMS service was originally designed for GSM system mobile phones, but now it can be used on almost any mobile phone system, such as 3G mobile phones.

SMS is designed based on the GSM network, so you can send text messages no matter which network segment you occupy