Promoting a pawn does not work

[sesteva]

First of all, thank you! Im really enjoying doing the drills in the app, bringing it easily from Lichess studies.

Issue: when I try to promote a pawn it throws an error. Only way fw is to refresh the page, yet it keeps failing at the same point.
Variation still shows as pending to be learnt.

Uncaught Error: Invalid move: {"from":"b7","to":"a8"} Immutable 29 <anonymous> https://chessdriller.org/study:69 promise callback* https://chessdriller.org/study:68 13.f55a944a.js:26:13021

[sesteva]

I've just checked svelte-chessground and it basically states "If you want a chessboard with legal moves and pawn promotion without additional code, you're looking for svelte-chess."

Any reason why you decided not to use svelte-chess instead?