This page illustrates the format of the request json data.
In order to use the append slide endpoint, you'll need to structure your slide payload in a certain way. Below is an example of that structure.
{"slide": {"id":null,"base_text":"Weighted Base (All Answering):ALL","table_text":"Q1","index":0,"layout": {"pptx_template":"Default","slide_layout_index":5,"slide_master_index":0 },"question_text":"Q1. Which of these have you done in the last week?" },"charts": [{"rows": [{"text":"Read a printed newspaper","visible":true }, {"text":"Visited a newspaper website","visible":true }, {"text":"Read a printed magazine","visible":true }],"columns": [{"text":"Total","selected":true,"items": [{"base":1949,"data": [43,41,25],"text":"Total","selected":true }] }, {"text":"Gender","selected":true,"items": [{"base":175,"data": [44,44,24],"text":"Male","selected":true }, {"base":434,"data": [42,39,27],"text":"Female","selected":true }] }],"view_settings": {"chart_type":"bar","placeholder_index":0 } }]}
For more information on the payload please check the payload details page.