rest api: standard way of requesting required input information before post [closed]

Consider a simple Rest API like this:

GET /products list my products
POST /products create a new product
GET /products/12 show information on a certain product

Now if I want to create a new product, I'd use the second endpoint, but don't know in advance which information I need to provide. Is there a defined way/ an actual standard, how I'd design an additional endpoint that provides this kind of "empty template" I need to fill with information for a successful post?Something like GET /products/template, or such?!

I didn't find anything during my research so far...Thanks in advance.