How to change the start position in Chessboard.js?

I am using the code given in the website https://chessboardjs.com/examples#5000.
Here, when I try to change the start position in the config, all the pieces snap back to the intial position when any piece is moved. I also tried using game.load('fen'), but it gives the same result. Any help regarding this would be greatly appreciated.

I want to change the starting position, like in the cases of puzzles where only some pieces are there but all the usual chess rules are followed.

I tried using game.load('fen') and also change the 'position' in 'configs'.

I figured this out later myself. The problem is that chessboard.js and chess.js use different types of FENs. In chessboard.js, the FEN is simply

'rnbqkbnr/ppp1pppp/8/3p4/4P3/8/PPPP1PPP/RNBQKBNR'

whereas in chess.js, there are additional elements at the end:
'rnbqkbnr/ppp1pppp/8/3p4/4P3/8/PPPP1PPP/RNBQKBNR w KQkq d6 0 2'

To achieve the desired result, change the position in the configs to the chessboard.js one

var config = {
                draggable: true,
                position: 'rnbqkbnr/ppp1pppp/8/3p4/4P3/8/PPPP1PPP/RNBQKBNR',
                onDragStart: onDragStart,
                onDrop: onDrop,
                onSnapEnd: onSnapEnd
            }

and load the chess.js board with its own FEN

var game = new Chess()
game.load('rnbqkbnr/ppp1pppp/8/3p4/4P3/8/PPPP1PPP/RNBQKBNR w KQkq d6 0 2')

I hope this solution helps someone in the future!