Implement simple nodejs with customizable refresh token time

I want to create a simple nodejs server’s where i can generate refreshtoken with customizable time to expire.

Currently im able to use the /oauth/token POST method to generate just an access token, how ever when i try to use the other methods like —>

curl --request POST \
  --url 'https://YOUR_DOMAIN/oauth/token' \
  --header 'content-type: application/x-www-form-urlencoded' \
  --data grant_type=authorization_code \
  --data 'client_id=YOUR_CLIENT_ID' \
  --data 'client_secret={yourClientSecret}' \
  --data 'code={yourAuthorizationCode}' \
  --data 'redirect_uri=https://YOUR_APP/callback'

In this case what is the {yourAuthorizationCode}, or what endpoints should i go about to achieve what im trying to get i.e have a random endpoint secured by auth0 by customizable refresh tokens