Amazon itself doesn't openly and publicly provide data related to Keyword search volumes. The sole similar data it shares is associated with the Impressions an advertiser gets using Sponsored Product Ads on Amazon, which are highly dependent on the bid.
Our Keywords Search Volume estimates are pulled from both Google's widely-trusted API as well as data from Amazon directly. Google data is pulled from the monthly search queries in its search engine and used as a proxy to assess the importance of a keyword outside Amazon. This is combined with our in-house estimation of search volumes based on various data sources and AI.
Keywords Search Volume estimate data for Walmart Marketplace is pulled only from Google.
Data is then updated monthly. Data for newly-tracked Keywords appear within 24 hours.