A running lnd node, either on a remote host and accessible from outside, or on the same host, in which case you can either start this container in "host network" mode, or use the container's gateway IP address to reach the host's localhost
Usage
Create a data directory on the host: mkdir data
Copy the tls.cert and invoice.macaroon from your lnd to the data directory
Run the container: docker run -d --name qr-code -v $(pwd)/data:/root/data -p 8080:8080 philippgille/qr-code -addr "123.123.123.123:10009"
Send a request to generate an invoice: curl http://localhost:8080/qr
Pay the invoice that's in the response body via the Lightning Network
Send the request again, this time with the preimage as payment proof (hex encoded) and the data as query parameter: curl -H "x-preimage: 119969c2338798cd56708126b5d6c0f6f5e75ed38da7a409b0081d94b4dacbf8" http://localhost:8080/qr?data=testtext
-addr string
Address of the lnd node (including gRPC port) (default "localhost:10009")
-dataDir string
Relative path to the data directory, where tls.cert and invoice.macaroon are located (default "data/")
-price int
Price of one request in Satoshis (at an exchange rate of $1,000 for 1 BTC 1000 Satoshis would be $0.01) (default 1000)