CSV -> Zoho Sign via Zoho Flow

I have an old and antiquated admin system that currently spits out a PDF application/contract that I upload in to Zoho Sign. Users then manually add signatures etc. and send it out.

I want the applicant to be able to edit their personal info, rather than it being fixed. I have created my template and my admin system can now spit out a CSV with all data I need for populating the template.

Unfortunately, Zoho Sign doesn't have a way to import the data in to a template, so I thought Flow might be a good workaround.

Tried Excel and Sheet as triggers, but due to various limitations (such as where the file must be located), neither are adequate.

Thought Creator might be another option - once a new entry is created, links to Sign via Flow and populates the data. This works great if I manually complete the form. If I use the "Import Data" menu option however, Flow doesn't recognise this as a new entry.

Does anyone have a better way that I can do this?