test.json

{
	"templateName": "sample_invoice.tx",
	"mergeBlocks": [
		{
			"name": "item",
			"mergeFields": [
				{
					"dateTimeFormat": "",
					"name": "qty",
					"numericFormat": "",
					"preserveFormatting": false,
					"text": "«qty»",
					"textAfter": "",
					"textBefore": ""
				}
			],
			"mergeBlocks": []
		}
	],
	"mergeFields": [
		{
			"dateTimeFormat": "",
			"name": "yourcompany_companyname",
			"numericFormat": "",
			"preserveFormatting": false,
			"text": "«YOURCOMPANY_COMPANYNAME»",
			"textAfter": "",
			"textBefore": ""
		},
		{
			"dateTimeFormat": "",
			"name": "invoice_no",
			"numericFormat": "",
			"preserveFormatting": false,
			"text": "«invoice_no»",
			"textAfter": "",
			"textBefore": "#"
		}
	]
}