Using Deluge To Merge and Download Document and Attach to Deal

Using Deluge To Merge and Download Document and Attach to Deal

I have a custom function that currently lives inside Zoho CRM and is triggered via a workflow rule. The custom function takes information from a deal and creates a merged document (zoho writer functionality), and then attaches that merged document to the deal. In an effort to save our workflow rules limit, I wanted to migrate this custom function to "Zoho Flow." Unfortunately, when I create a custom function and copy and paste the code into the custom function in Zoho Flow, I get an error saying "zohowriter connection doesnot exists at line number 1. Resolve the errors and try again"

My "zohowriter" connection was created in Zoho CRM. I don't know if I have to create a different connection for Zoho Flow. Would greatly appreciate it if someone could help me figure out what I need to change for this to work through Zoho Flow.

For reference, I used this for instructions on the custom function and it DOES work if you do it from CRM: 

Here is the full code:

void testmvk(int potid, string xxxxx)
{
potinfo = zoho.crm.getRecordById("Deals",potid);
fields = zoho.writer.getMergeFields(xxxxx,"zohowriter").get("fields").distinct();
val = Collection();
for each  rec in fields
{
field = ifnull(potinfo.get(rec),"");
if(field.contains("{") && field.contains("id"))
{
val.insert(rec + ":" + field.get("name"));
}
else
{
val.insert(rec + ":" + field);
}
}
cmp = "{" + val.toString() + "}";
ddata = List();
ddata.add(cmp.toMap());
dmp = Map();
dmp.put("data",ddata);
mp = Map();
mp.put("merge_data",dmp);
file = zoho.writer.mergeAndDownload(xxxxx,"pdf",mp,"zohowriter");
update = zoho.crm.attachFile("Deals",potid,file);
}