Automatically assign template to documents for signing

Is there a way to automatically assign a template to documents for signing?

We have a very standard PDF that is given to us by a 3rd party for deliveries.

We are doing the deliveries but need to collect staff details when we complete these deliveries.

So we just need one template to be applied for all documents.

Is there a way we can automate this process so that when we need a new PDF setup for delivery we can email/send/use cloud storage to save the file, it will then pull out the file, assign the template and email it to us?