Can I underpromote when I have the „always promote to a Queen” option on?

Hello!

I am playing many bullet games and I have the option to always promote to a Queen activated. However I managed to set up the Lasker trap which involves underpromotion to a Knight at some point. Unfortunately I was Unable to find a combination of keys that would allow me to instantly change the main setting of always promoting to a Queen.

Is there any way to do this? Thank you.

No, not on chess.com

Lichess has a good in between: premoving a promotion = queen, but non-premove promotion = you get to choose 

https://support.chess.com/article/362-what-chat-commands-can-i-use-in-live-chess

According to the site help, press and hold the ALT key for a one-off disable of the auto-queen.

Thank you! It works!

> press and hold the ALT key for a one-off disable of the auto-queen

Is there any way to achieve this behavior in the mobile app? 

what if you are playing on macbook? what is the ALT key equivalent.

On a Mac try the Option key.