Notice the OP did not ask how to search for THEIR OWN repls. Until one creates a LOT, this is not very useful. Your answer, and the docs, assume they would only want to search the repls that they made.
The REAL useful, and in my opinion necessary, feature is to search ALL public repls. For example, if I wanted to know "does anyone have example code that shows me how to use Enzyme". Right now there seems to be no way to know. So now you have to go to CodePen to search for code snippets.
Your "talk" section REALLY needs a search feature too! How can anyone see if their question has been asked before?
The repls are indexed at google, so you just need to search using google dorks.
Click on Search(google search).
api query site:repl.it