CHESS RULES FOR BEGINNER

Here are some basic rules of chess for beginners:
How pieces move
The king can move one square in any direction, the rook can move any number of squares horizontally or vertically, the bishop can move any number of squares diagonally, the queen can move any number of squares in any direction, and the knight can jump in an "L" shape. Pawns can move up the board one square, except on their first move when they can move two squares. Pawns can't move backward, but they can capture pieces diagonally one square away, which is different from how they move.
Check and checkmate
The king is the most important piece, so when an opposing piece threatens to capture it, the player must avoid the threat. This is called being in check. Learning basic checkmates can help players avoid quick losses and win games.
Castling
This move helps keep the king safe and develop a solid defense and strategy.
Pawn promotion
When a pawn reaches the farthest rank from where it started, it can become any other piece, except a king. For white pawns, this is the eighth rank, and for black pawns, it's the first rank.
En passant
This capture must be done immediately after a pawn moves two squares

You can take the pawn en passant as soon as the opportunity arises or decline. But declining means you lose the ability to capture that way for the rest of the game should another chance occur (as I understand the move).

Honestly half my games I dont take en passant