when creating a new message (sms), quick responses can also be used and sent. quick replies can be added/edit/deleted in the settings and can contain up to 200 characters. instead of entering text, the quick response inserts the predefined text into the text field, thus saving typing.

Android 10 (One UI 2.0)
Step 1:  Open the  Messages -App
Step 2:  Open a  Conversation
Step 3:  Tap on  Add
Step 4:  Tap on  Quick response
Step 5:  Choose desired  Quick response
Step 6:  Tap on  Send
  1. Open the Messages-App
  2. Open a Conversation
  3. Tap on Add
  4. Tap on Quick response
  5. Choose desired Quick response
  6. Tap on Send

Samsung Instructions