How do you get the Season 2020 - Flex Master Icon?
It was a ranked reward. Riot's description in the client reads: “This icon was earned by finishing Master in Flex Queue in Season 2020”
Is the Season 2020 - Flex Master Icon still available?
No. The Season 2020 - Flex Master Icon was a ranked reward. To earn it, you had to reach Master in Flex during Season 10 (2020). Riot does not hand out past ranked rewards again, so you cannot earn this icon anymore.
Season 2020 - Flex Master Icon is one of the rarest LoL summoner icons.
