Installation
BTCPay Server
First of all you need a running BTCPay Server instance. If you still don't have one, then set it up.
Node-RED
To build your apps visually, you also need to install Node-RED, a low-code programming tool for event-driven applications.
BTCPay Nodes
And finally, to enable interaction between Node-RED and BTCPay Server, install BTCPay Nodes.