New backend. How to connect?

@Arjan

Downlink messages
ttnctl downlink 0000000002012910 'Hello back!' 40m
The last argument specifies the lifetime of the message. The message expires if not sent to the node within the specified time frame.

If you use ttnctl subscribe the message is shown decoded in my experience. An ABP node registered with both keys shows the data and even warns when ascii data is being received.
Using RN2483:
mac tx uncnf 1 302E3030303030302C302E303030
Result:
$ ttnctl subscribe
INFO Subscribing to uplink messages from all devices in application 70b3d57edXXXXXXXXX
INFO Subscribed. Waiting for messages...
INFO 0.000000,0.000000 DevEUI=000000000XXXXXXXX
WARN Sending data as plain text is bad practice. We recommend to transmit data in a binary format. DevEUI=00000000XXXXXXXX