API call with hundreds of parameters

I’m integrating an API that will send data to a document generation service to generate templates in Word format. There are multiple documents that will be generated. My issue is that I have over 250 parameters to enter for the API call which is essentially the entirety of my app’s main datapoints that need to be rendered in documents.

Initially I thought I’d have one API call per document needed (which means there’d be about 6 or 7 API calls). Users can then trigger the corresponding API call for the document they need. However, I realised that I’d not have to only manually create multiple API calls for each document (and create new calls for each new document after that), but also maintain them and update them each if there were any update or changes.

The alternative to the above, was to only use the exact number of parameters I need of that document (instead of the 250), but similarly, it’s still quite a time consuming process and I’d need to add new parameters to the API as I use them in the document.

I’m not leaning more towards having one API call, having all 250 parameters specified within it and maintain only one integration. The only downside to this is that all my documents will be generated from this single API integration. So instead of having each document as API call, users will needlessly have all documents generated when they might just need a specific document.

Are there any other ways to accelerate building this integration?

(Can’t use shared parameters as each value needs to be dynamic)