You most likely have HDR turned on which will disable the flash option. Turn it on auto in the settings when you're in auto mode and the flash option will be available to use.For quick shots like what i posted, i shouldn't have to go into manual mode. Another thing i noticed about auto mode is i can't use flash at all. I cannot select it for anykind of fill light. On my S7E, i was able to do so and auto made produced better low light pics.
Quick shot no processing. //uploads.tapatalk-cdn.com/20171130/dbf34f25013e760b5a6418215ec924ba.jpg
Shot in Google camera zsl port and edited in Lightroom. As all my v30 photos are.
The V30 will never be a great auto shooter like the pixel or note 8. But if you are willing to put in a bit of work in post processing, the sensor produces some top quality photos. //uploads.tapatalk-cdn.com/20171202/57104bd40b38bc0c9c620397c3d9ca47.jpg
Quick shot no processing. //uploads.tapatalk-cdn.com/20171130/dbf34f25013e760b5a6418215ec924ba.jpg