KeePassXC can’t be run in headless mode, and the GUI is tightly coupled to the app. You have to have all of X installed, and have a display running, to run it.

Here’s the runtime dependencies of KeePassXC:

linux-vdso.so.1
libQt5Svg.so.5
libqrencode.so.4
libQt5Concurrent.so.5
libpcsclite.so.1
libargon2.so.1
libQt5Network.so.5
libQt5Widgets.so.5
libbotan-3.so.5
libz.so.1
libminizip.so.1
libQt5DBus.so.5
libusb-1.0.so.0
libQt5X11Extras.so.5
libQt5Gui.so.5
libQt5Core.so.5
libX11.so.6
libstdc++.so.6
libm.so.6
libgcc_s.so.1
libc.so.6
/lib64/ld-linux-x86-64.so.2
libgssapi_krb5.so.2
libproxy.so.1
libssl.so.3
libcrypto.so.3
libbz2.so.1.0
liblzma.so.5
libsqlite3.so.0
libdbus-1.so.3
libudev.so.1
libGL.so.1
libpng16.so.16
libharfbuzz.so.0
libmd4c.so.0
libsystemd.so.0
libdouble-conversion.so.3
libicui18n.so.75
libicuuc.so.75
libpcre2-16.so.0
libzstd.so.1
libglib-2.0.so.0
libxcb.so.1
libkrb5.so.3
libk5crypto.so.3
libcom_err.so.2
libkrb5support.so.0
libkeyutils.so.1
libresolv.so.2
libpxbackend-1.0.so
libgobject-2.0.so.0
libcap.so.2
libGLdispatch.so.0
libGLX.so.0
libfreetype.so.6
libgraphite2.so.3
libicudata.so.75
libpcre2-8.so.0
libXau.so.6
libXdmcp.so.6
libcurl.so.4
libgio-2.0.so.0
libduktape.so.207
libffi.so.8
libbrotlidec.so.1
libnghttp3.so.9
libnghttp2.so.14
libidn2.so.0
libssh2.so.1
libpsl.so.5
libgmodule-2.0.so.0
libmount.so.1
libbrotlicommon.so.1
libunistring.so.5
libblkid.so.1

I don’t know why it links to a systemd library. Here are the runtime dependencies of rook:

linux-vdso.so.1
libresolv.so.2
libc.so.6
/lib64/ld-linux-x86-64.so.2

Don’t get me wrong: KeePassXC is one of my favorite programs. But don’t leave it running all the time, and it can’t be run on headless systems.