There is a known problem of 'quacking' sound during braking. It occurs due to the ABS module peculiarity when air gets inside. It does not affect my safety in any way. There is an official bulletin from Toyota on solving this issue. The only way to completely get rid of it is by replacing the ABS block with a new one (not remanufactured), produced after 2018.

ABS LS IV Bulletin

And instructions for proper brake bleeding here