=================================== EXAMPLE with empty page attr ====================
curl --request POST \
  --url http://api.phoenix-widget.com/api/v1/rtb/5b3336264f32fe4088e5881e/5b46129a4f32fe7c08da1b75 \
  --header 'content-type: application/json' \
  --data '{
	"id": "d49347f4-22f0-4265-b88b-98546aa9557d",
	"site": {
		"id": "140312",
		"domain": "russian.rt.com",
		"page": ""
	},
	"device": {
		"ua": "Mozilla\/5.0 (Windows NT 5.1) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/49.0.2623.112 Safari\/537.36",
		"ip": "91.124.3.134",
		"language": "ru"
	},
	"user": {
		"id": "eaa02b76-6cd9-43de-a431-430a6ea04c59"
	},
	"at": 1,
	"cur": ["USD"],
	"imp": [{
		"id": "1",
		"native": {
			"ver": "1.1",
			"request": "{\"assets\":[{\"id\":3,\"required\":1,\"img\":{\"wmin\":400,\"hmin\":250,\"type\":3,\"mimes\":[\"image\\\/png\",\"image\\\/jpg\"]}},{\"id\":1,\"required\":1,\"title\":{\"len\":100}},{\"id\":2,\"required\":1,\"data\":{\"type\":1,\"len\":25}}],\"plcmttype\":4,\"plcmtcnt\":3,\"ver\":\"1.1\",\"context\":1}"
		},
		"secure": 1,
		"bidfloor": 0.01
	}]
}'


=========================== not empty (valid request)=========================================
curl --request POST \
  --url http://api.phoenix-widget.com/api/v1/rtb/5b3336264f32fe4088e5881e/5b46129a4f32fe7c08da1b75 \
  --header 'content-type: application/json' \
  --data '{
	"id": "d49347f4-22f0-4265-b88b-98546aa9557d",
	"site": {
		"id": "140312",
		"domain": "russian.rt.com",
		"page": "https:\/\/russian.rt.com\/sport\/news\/556193-prichina-udaleniya-ronaldu-valensiya?utm_medium=referral&utm_source=lentainform&utm_campaign=russian.rt.com&utm_term=1272982&utm_content=6685997"
	},
	"device": {
		"ua": "Mozilla\/5.0 (Windows NT 5.1) AppleWebKit\/537.36 (KHTML, like Gecko) Chrome\/49.0.2623.112 Safari\/537.36",
		"ip": "91.124.3.134",
		"language": "ru"
	},
	"user": {
		"id": "eaa02b76-6cd9-43de-a431-430a6ea04c59"
	},
	"at": 1,
	"cur": ["USD"],
	"imp": [{
		"id": "1",
		"native": {
			"ver": "1.1",
			"request": "{\"assets\":[{\"id\":3,\"required\":1,\"img\":{\"wmin\":400,\"hmin\":250,\"type\":3,\"mimes\":[\"image\\\/png\",\"image\\\/jpg\"]}},{\"id\":1,\"required\":1,\"title\":{\"len\":100}},{\"id\":2,\"required\":1,\"data\":{\"type\":1,\"len\":25}}],\"plcmttype\":4,\"plcmtcnt\":3,\"ver\":\"1.1\",\"context\":1}"
		},
		"secure": 1,
		"bidfloor": 0.01
	}]
}'