Amazon Search Terms, Market Basket, and Repeat Purchase reports are part of Brand Analytics. As a result, these report is only available to sellers or vendors who own a brand (see Amazon Brand Registry). Per Amazon, an authorizing Seller Central or Vendor Central account must be internal to the brand and responsible for selling the brand in the Amazon store.
Here is an example of a permission error you may see if you are access restricted:
Checking Your Permissions
Sellers: If you are not able to access Brand Analytics, go to the Brand Benefit Eligibility page where you can click ‘Review my eligibility’ to correct your status and gain access to Brand Analytics reports.
Vendors: Confirm your brand is registered in Amazon Brand Registry. Also, make sure the authorizing user account has all reporting access types (Operations, Finance, Digital, etc.) enabled.
Fixing Permissions Issues
Sellers
If you see an error message stating “You do not have permission to access this page,” request the Primary Account Administrator grant you permission to “Amazon Brand Analytics” on the Global User Permissions page.
You may also see the following notice on the Brand Benefit Eligibility page:
You are designated as a secondary user and do not have permission to view this page.
To resolve this, you must contact the Primary Account Administrator to grant "View" permissions under - Settings -> User Permissions -> Manage Global Permissions -> Select user and set the status to “View” for “Brand Benefit Eligibility” under the “Performance” category.
Vendors
To validate permissions in your vendor account, please check your permissions as shown below. Unlike Sellers, there is no Brand Benefits page in Vendor Central. As a result, you need to assess the permissions granted to your Vendor Central user account.
For additional permissions information, see How To Configure Amazon Selling Partner Permissions or Troubleshooting SP-API User Permissions.