App KeepassXC

I sent the following topic to the support of GitHub about the app KeepassXC:
I am a very often user of keepassxc and I can’t find in configuration options how to increase the font size. The letters are foo small
I think that persons that have some visual deficiency have to use a magnifying glass to read the screen’s information…

The GitHub support sent me the following answer:
We use the same font size that your system uses, or at least what Qt thinks is the system font size. You probably need to upscale the UI, try using one of these environment variables to properly scale the UI to your screen size (this is a notorious problem on Linux with Qt): High DPI Displays | Qt 5.15

Well, I don’t know what is UI and I don’t know also how to set the environment variables.
Can you help me with a step by step procedure in order I can solve this problem?

Hi Nogueira.

UI is really GUI: “Graphical User Interface” - just the window that you see on your screen.

The scale factors mentioned on your link don’t exist on my Ubuntu system, but you can check yours by issuing the following commands:

echo $QT_SCALE_FACTOR

then

echo $QT_AUTO_SCREEN_SCALE_FACTOR

then

echo $QT_SCREEN_SCALE_FACTORS

If any of these results in any text (rather than a blank line) then you might be in business.

Broadly speaking, I rarely change environment variables, and you are right to be wary.
My own solution to inconvenient text font sizes (which seems to be a more frequent problem these days) is simply to use the Ctrl++ method to increase the size. That is: while holding down the Ctrl key, tap the + key as many times as necessary to increase the text size to whatever you want. Use Ctrl+- to reduce the size.
Hope this helps a bit. Best I can do.
Keith