That was my impression too, signing a 3 year deal in 2020 for ~$400 to $450 million/year.
> More than 90 per cent of Mozilla's funding comes from web search providers that pay for the right to be the default search engine in Firefox in their regions. According to the organization's latest financial figures [PDF], $430m of its 2018 total revenue of $451m came from those internet giants – primarily Google, we understand. These deals were due to be renewed or renegotiated by November this year.
[1] https://www.theregister.com/2020/08/14/mozilla_google_search...
I believe it's listed under royalties and also receivables in the annual report, though that does not specify Google specifically, but you can look at the numbers and figure they are a large portion if the news was accurate.
[2] https://assets.mozilla.net/annualreport/2020/mozilla-fdn-202...