Which direction is the light source coming from in the dark images?
For example, if it coming from behind the subject, a common occurrence known as backlighting, put some light from the front toward the subject — you can do this with a flash unit, or by using various types of colored reflectors. Or, use long exposures with various grades and types of graduated neutral density filters to bring out the dark areas without blowing out the highlights. Or try bracketing exposures. There is a technique called ETTR, expose to the right, which will bring out shadow detail but risks blowing out the brighter sections.
This may help in understanding DR settings as well as Dynamic Range Priority:
https://www.jmpeltier.com/fujifilm-dynamic-range-settings/
p.s. The situation you are describing has been one photographers have struggled against since cameras and photographers have been around.