Like Qwerty said you know have to Fork a Repl to be able to run it. Due to recent changes this is the case, and you will have to Fork unless the creator Deploys the Repl, in that case you will be able to run it like normal. These changes apply to normal console based programs like Python and C, but there is no way to deploy them unless you set up some kind of server to run it (like Flask for Python) and use an Autoscale Deployment.