SMS messages can be sent on the Samsung device with the pre-installed "Messages" app. As has been the case for many years, a maximum of 160 characters per SMS can still be sent. If a message is longer, the text is sent as a whole, but is divided into several SMS. Messages (SMS) can be sent on the Samsung device to a single contact/phone number or to multiple as well as groups.

Android 10 (One UI 2.0)
Step 1:  Open the  Messages -App
Step 2:  Open a  Conversation  or tap on  New
Step 3:  Enter a  message
Step 4:  Tap on  Send
  1. Open the Messages-App
  2. Open a Conversation or tap on New
  3. Enter a message
  4. Tap on Send

Samsung Instructions