Capturing IP cam stills with a shell command

I’m trying to get my IP camera to take stills whenever my door sensor is activated and I’m not home, or when I flip a boolean.

My shell command is:
snapshot: wget "http://<IP>:<PORT>/snapshot.cgi?user=<USER>&pwd=<PASSWORD>" -O {{filename}}

And my script is:

    - service: shell_command.snapshot
      data_template: 
        filename: '{{/home/pi/snapshot1.jpg}}'
    - delay:
        seconds: 1
    - service: shell_command.snapshot
      data_template: 
        filename: '{{/home/pi/snapshot2.jpg}}' 

If I run the shell command in putty with the directory instead of {{filename}} then it works, but when I try it through Home Assistant I get:

17-02-24 11:47:07 ERROR (MainThread) [homeassistant.bootstrap] Invalid config for [script]: expected a dictionary for dictionary value @ data['script']['intruder_alert_image']. Got None
extra keys not allowed @ data['script']['\xa0\xa0  - service']. Got 'shell_command.snapshot'
extra keys not allowed @ data['script']['\xa0\xa0\xa0 - delay']. Got None
extra keys not allowed @ data['script']['\xa0\xa0\xa0\xa0\xa0 data_template']. Got None
extra keys not allowed @ data['script']['\xa0\xa0\xa0\xa0\xa0\xa0  filename']. Got '{{/home/pi/snapshot1.jpg}}'
extra keys not allowed @ data['script']['\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0seconds']. Got 1
extra keys not allowed @ data['script']['\xa0\xa0alias']. Got 'Intruder Image'
extra keys not allowed @ data['script']['\xa0\xa0sequence']. Got None. (See /home/homeassistant/.homeassistant/configuration.yaml, line 273). Please check the docs at https://home-assistant.io/components/script/

Help, please?

I’m keen to do same, can anyone advise. If I solve it I’ll share here also.