We can search a stored conversation in the messages app of the OnePlus smartphone for searched terms or keywords.

After entering the keyword we can use virtual arrow keys to search between the results found and those marked in yellow.

Android 10 | OxygenOS 10.0
Search conversation -  Open the  Messages app
Search conversation -  Choose a  conversation
Search conversation -  Tap on  Search
Search conversation -  Enter a  keyword
Search conversation -  Tap on  Search
  1. Open the Messages app
  2. Choose a conversation
  3. Tap on Search
  4. Enter a keyword
  5. Tap on Search

OnePlus Instructions