onPreCheckoutQuery

inline fun Bot.onPreCheckoutQuery(sequence: SubscribeSequence = NORMAL, crossinline processor: suspend (Event, preCheckoutQuery: PreCheckoutQuery) -> Unit)

Equivalent to the following:

// process or preProcess
bot.subscribe<PreCheckoutQuery>(sequence, PRE_CHECKOUT_QUERY_NAME) { event, preCheckoutQuery ->
    // ...
}