Google Merchant Center is a way to help get your product(s) into Google and make it available to shoppers using Google. Which means, anyone who searches for the keyword on Google search, you should show up as a suggested seller.
Now, Google Merchant can only be linked with websites / selling channels where you have your own domain setup, such as:
BigCommerce
Shopify
WooCommerce
Before connecting SellerChamp with your Google merchant account:
Once the above steps are completed, you simply need to connect your Google Merchant account with SellerChamp.
Learn more about Google Merchant Center