Instant draw
"5.2 b. The game is drawn when a position has arisen in which neither player can
checkmate the opponent’s king with any series of legal moves. The game is said to
end in a ‘dead position’. This immediately ends the game, provided that the move
producing the position was legal."
https://www.fide.com/FIDE/handbook/LawsOfChess.pdf
Is this kind of position an instant draw or do the players have to play it out until the 50 move rule takes action?