[Product Vendors] Setting the vendor of a product via php

Im trying to automate product creation with php. I succesfully create products and set things like the title or category.
Im using “Product Vendors”, so every product can have a vendor, which i can set manually.
Now i want to set the vendor via php. I already searched the internet and only found a meta-key (“wcpv_product_vendors”), which im not sure if its the right one.