How can I get the content of a .json file which is in an iframe ? The .json file is https://dashboard.gfpg.co.uk/public/api/siteinfo/edbb2d05-6f26-11e7-ae00-06b1fafa42a3.json
and consists of merely
{"name":"Drove","id":"TDRVE-1","mw":0,"kw":0,"gas":755227},
which displays in the iframe. Thanks.