On https://railway.com/heroku there is a button that says 'Read the migration docs'. It links to https://docs.railway.com/tutorials/migrate-from-heroku which results in a page not found.

The actual guide is at: https://docs.railway.com/platform/migrate-from-heroku

It says:

click on the service

click Variables tab

open the command palette using CMD + K or Ctrl + K.

search for Import variables from Heroku

confirm the Heroku service and hit Enter

When I try to do this, no such service is visible.