If it is the complete msg object then you would have to use each property in that in the inject node.
Or
In a function node
msg = paste your copied object here
return msg;
example flows
[{"id":"309f3c05.abf754","type":"inject","z":"c791cbc0.84f648","name":"","props":[{"p":"payload"},{"p":"another","v":"[1,2,3]","vt":"json"},{"p":"_msgid","v":"aa9dc125.4cb08","vt":"str"},{"p":"topic","v":"156","vt":"num"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"[{\"series\":[\"\"],\"data\":[[12,12,14]],\"labels\":[\"340\",\"350\",\"360\"]}]","payloadType":"json","x":150,"y":1580,"wires":[["72cdbe7f.04fa88"]]},{"id":"371715.989fc0ec","type":"inject","z":"c791cbc0.84f648","name":"","props":[{"p":"_msgid","v":"aa9dc125.4cb09","vt":"str"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":140,"y":1680,"wires":[["c8552470.4610e8"]]},{"id":"c8552470.4610e8","type":"function","z":"c791cbc0.84f648","name":"","func":"msg = {\n \"payload\":[\n {\n \"series\":[\"\"],\n \"data\":[[12,12,14]],\n \"labels\":[\"340\",\"350\",\"360\"]\n }\n ],\n \"topic\":156,\n \"_msgid\":\"aa9dc125.4cb08\",\n \"another\":[1,2,3]\n}\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":370,"y":1680,"wires":[["4f1482a1.8a0444"]]},{"id":"4f1482a1.8a0444","type":"debug","z":"c791cbc0.84f648","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":540,"y":1680,"wires":[]},{"id":"72cdbe7f.04fa88","type":"debug","z":"c791cbc0.84f648","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":440,"y":1580,"wires":[]}]