According to [1], all imports from Russia to Germany in March were 4B EUR, so rather $139M/day, not $1B/day. Maybe that is the amount for all of the EU (with Germany then contributing 13.9%)?
[1] https://www.destatis.de/DE/Presse/Pressemitteilungen/2022/03...
The source you provided (thank you) reads: “Proceeds from the sale of Russian oil and gas amount to around $1bn (£770m) a day”. In the context of the article, it is misleading, unfortunately; in itself it could even mean ‘from everyone’. Itʼs probably the number given by Borrell.
[1] https://www.euronews.com/my-europe/2022/04/06/eu-has-spent-3...
[2] https://tfiglobalnews.com/2022/04/08/eu-gave-e1-billion-in-m...
[3] https://www.ndtv.com/world-news/minister-says-eu-giving-russ...