Use the Search Terms module to find poor performing search terms or ASIN targets and them as negative keywords to your campaigns.
Search terms are a group of words that an Amazon customer types into the search bar where your ad is displayed on the search results page.
ASIN targets are a specific product's ASIN that is being targeted where your ad is displayed on the targeted ASIN's product page.
Navigate to https://app.merchjar.com/search-terms
Find the search term you would like to add as a negative keyword.
Click the Add Negative Keywords button.
Select the match type for the negative keyword.
Use the Negative Keyword field to modify the negative keyword being added if needed.
Use the selection boxes to select one or more ad groups to add the negative keyword to.
Click Create Negative Keywords button.
Your negative keywords have now been added to the selected ad groups.