Conversations or chats that have been archived for safekeeping can also be restored at any time to be displayed again on the start page of the OnePlus smartphone's messages app.

Note: A conversion can also be opened or viewed directly from the archive.

Android 10 | OxygenOS 10.0
Step 1:  Open the  Messages app
Step 2:  Open the  menu
Step 3:  Tap on  Archived
Step 4:  Tap and hold a  conversation
Step 5:  Tap on  Restore/unarchive
  1. Open the Messages app
  2. Open the menu
  3. Tap on Archived
  4. Tap and hold a conversation
  5. Tap on Restore/unarchive

OnePlus Instructions