No. Under the FIDE Laws of Chess, en passant is an optional capture: a player who has the chance may take it or make any other legal move instead.
The rule, Article 3.7.3.1, says a pawn standing on the same rank and an adjacent file as an opponent’s pawn that has just advanced two squares from its starting square “may capture” it as though it had moved only one square. Article 3.7.3.2 adds that the capture is legal only on the very next move, so a player who declines it loses the option for good. There are two situations where it can become required in practice. If en passant is the only legal move available, the player must play it, because the players move alternately and passing is not allowed. In over-the-board play, the touch-move rule in Article 4.3 also applies: a player who deliberately touches an opponent’s pawn that can be captured must capture it, and that can mean capturing en passant. In notation, the move may be marked with “e.p.”, as in exd6 e.p.
Source: FIDE Handbook, Laws of Chess (Articles 1.2, 3.7.3, 4.3, and Appendix C)
Image: Chess game Staunton No. 6, by Wilfredor, CC0, via Wikimedia Commons.