Before you begin
Consider the following example of how to include parameters in the legacy options of the Composer API request body:
"LegacyOptions": {
"sc0": "1",
"sc1":"attachments",
"DS7": "12",
"CongaEmailTemplateId":"a068a00002kbQn5AAE",
"EmailToId":"0038a00002zvJBiAAM",
"EmailAdditionalTo": "abc@conga.com"
}
CODE
For more information, you can also see Document Generation Using Apex Call.