No. Once you click Bet and the Limbo round begins, your selected bet amount and multiplier are locked in and cannot be changed.
The game instantly generates a random multiplier based on your selected settings. If the generated multiplier is equal to or higher than your target multiplier, the bet wins. If the result is lower than your selected multiplier, the bet is lost.
To use different settings, wait for the current round to finish and adjust your bet amount or multiplier before placing a new wager.