Hello all! Cavachon puppy!

Ok thanks to be honest where I live most shih tzu or bichon mixers are called boomers.
Speaking from the point of view of boomers they can be quiet verbal.

can you identify triggers that set her off or is this just random barking if you can see triggers you can work to desensitize for example my dog used to bark at the doorbell so we did this whole exercise where my daughter stood outside and rang the doorbell with the door open so that he could see it was her and if he didn't bark he got a treat then we closed the door and she rang the doorbell and if he didn't bark he got a treat so he got used to the doorbell being a positive noise now the doorbell rings and he usually ignores it.
if you can identify a trigger you can use a similar technique to work to get your dog used to hearing the noise and not barking.

If the barking seems to be random youre dog is probably trying to get your attention , he wants to tell you something, take notice , if you stand up will the dog move and go to its food bowl water bowl toys etc are they trying to tell you they're bored they're hungry or thirsty?

never just dismiss barking as noise making because normally it isn't. The dog is trying to communicate it's up to you to find out what that communication is about ..