I am using Google channel plugin, for google shopping ads, products have been successfully updated. have to change the attributes of a few products and looking to manually sync data with google merchant, is there any way out to fetch Datafeed at Google merchant..
Whenever you make a change, Shopify should submit the product again and Google is updated within 24 hours.
There is no way for you to manually submit the data in the content API. However if there is a bug, then you can report it to Shopify and they will force push the data.
Yes, you can download your feed from Google Merchant Center (see following screenshot) and then create a Supplemental Feed.
What attributes are you hoping to manually override?
@alex_marketlabs By doing your method, all content will be overwritten by the manually generated feed, which causes issues when you change data in Shopify. In this case it will not be updated in Google Merchant Center, due to the supplement feed.
Also when using Content API, you can not download data as you explained, you can do this by going to Google Merchant Center > Products > All Products > click on the download icon.
The correct way is to contact Shopify to force push the product data, or use a data feed solution that allows you to manually pull and push data.