If you want to get a taste of the Node-RED interface, no server provided so flow execution is not possible,then checkout https://deadred.flowhub.org

Alternatively, check out the source code at https://github.com/gorenje/cdn.flowhub.org and run it locally or somewhere else.

There are SaaS offerings for Node-RED or you can install it yourself but there isn't a one-click-Node-RED experience but https://deadred.flowhub.org provides that by being a serverless, static frontend-only version.