Telegraf.conf - inputs.exec - debug isn't offering anything

Please help me correct this inputs.exec. I do not see the data being written to influx, and debug isn’t offering anything useful. I have the following in my telegraf.conf

[[inputs.exec]]
  interval = "5s"
  commands = ["/usr/local/bin/myip"]
  timeout = "5s"
  data_format = "json"
  name_suffix = "_myipaddr"

Debug isn’t offering anything.

# telegraf --debug --config /etc/telegraf/telegraf.conf --test
2020-05-26T00:49:54Z I! Starting Telegraf 1.14.3
# 

/usr/local/bin/myip

#!/bin/sh

ipaddr=`/sbin/ifconfig tun0 | grep 'inet' | cut -d: -f2 | awk '{print $2}'`
printf '{"ipaddr": "%s"}\n' $ipaddr

I’m not a linux user, can you add the actual output of the script?
For what I see, you are missing several Json input format parameters (like json_name_key), see the docs here