If, when creating a project, you specified the Editor type — Template Builder ("type": "tb") in the Task Interface parameters (view_spec), then specify the configuration for Template Builder in serialized JSON format in the config parameter.
Be sure to serialize the JSON code before passing it as the config parameter value.
Example of serialized JSON code
"config": "{\"view\": {\"type\": \"view.list\", \"items\": [{\"type\": \"view.image\", \"ratio\": [1, 1], \"rotatable\": true, \"url\": {\"type\": \"data.input\", \"path\": \"image\"}}, {\"type\": \"field.button-radio-group\", \"label\": \"What type of shoes do you see?\", \"options\": [{\"label\": \"Boots\", \"value\": \"boots\" }, {\"label\": \"Sneakers\", \"value\": \"sneakers\"}, {\"label\": \"Other\", \"value\": \"other\"}], \"validation\": {\"type\": \"condition.required\", \"hint\": \"choose one of the options\"}, \"data\": {\"type\": \"data.output\", \"path\": \"result\"}}]}, \"plugins\": [{\"type\": \"plugin.toloka\", \"layout\": {\"kind\": \"scroll\", \"taskWidth\": 500}}, {\"1\": {\"type\": \"action.set\", \"data\": {\"type\": \"data.output\", \"path\": \"result\"}, \"payload\": \"boots\"}, \"2\": {\"type\": \"action.set\", \"data\": {\"type\": \"data.output\", \"path\": \"result\"}, \"payload\": \"sneakers\"}, \"3\": {\"type\": \"action.set\", \"data\": {\"type\": \"data.output\", \"path\": \"result\"}, \"payload\": \"other\"}, \"type\": \"plugin.hotkeys\"}]}"