'You never know what kind of place you're going to get a picture of unless you're in the field.
There aren't a few photo jobs like that.
That's where a strobe comes in handy. I use a combination of Profoto A1 (two units) and Profoto B10 Plus, depending on the expected shooting environment.
Examples of strobe use 1
All the photos in this article were taken with the Profto A1 bounced off the ceiling (wall).
The scene in the conference room could be taken with steady light (in this case, fluorescent light), but if you shine a little light on the subject, it will be easier to lift it during RAW development.
Examples of strobe use 2
Next, the location in this photo is so dark that it's impossible to take a picture with steady light.
The B10 Plus is used as the umbrella main light to illuminate the subject, and the gridded A1 is held up to the product, a laptop PC, to highlight and shadow the edges and emphasize its presence.
It's almost the same here.
Since the theme is "Creators and PCs," the light is used to highlight both, while the shadows that fall on the walls directly express the hardships that lie behind the creation.
If you don't have one for Leica, use the manual!
It's convenient to have one, or preferably two, strobes, but here's the problem.
Most strobes are available for Canon, Nikon, Sony, and other manufacturers, but almost certainly not for Leica.
The answer is, "Use the manual.
In general, TTL (flash amount adjustment) is not available when using a camera other than the manufacturer's camera, but you can set the flash amount manually.
If you're not shooting events, weddings, or other events where you have to use the clip-on to take a variety of shots while changing situations, you shouldn't have much trouble with manual operation (just in case, check the operation at the store before purchasing).
