G'day @thmsh and welcome to linux.org
fvwm is beyond my paygrade but we have a number of members with many different talents.
I'll mention a few and this will alert them - if they know of it I am sure they will be along.
@JasKinasis , @JulienCC , @dos2unix for starters.
if you don't mind......, comrade.I'll look up the docs for fvwm and see if I can work it out!
th@debian:~$ neofetch
_,met$$$$$gg. th@debian
,g$$$$$$$$$$$$$$$P. ---------
,g$$P" """Y$$.". OS: Debian GNU/Linux 10 (buster) x86_64
,$$P' `$$$. Host: B360M-D2V
',$$P ,ggs. `$$b: Kernel: 4.19.0-6-amd64
`d$$' ,$P"' . $$$ Uptime: 3 hours, 1 min
$$P d$' , $$P Packages: 2172 (dpkg)
$$: $$. - ,d$$' Shell: bash 5.0.3
$$; Y$b._ _,d$P' Resolution: 1280x1024
Y$$. `.`"Y$$$$P"' WM: fvwm
`$$b "-.__ Theme: Breeze [GTK2/3]
`Y$$ Icons: breeze [GTK2/3]
`Y$$. Terminal: xterm
`$$b. CPU: Intel i5-8500 (6) @ 4.100GHz
`Y$$b. GPU: Intel UHD Graphics 630
`"Y$b._ Memory: 1902MiB / 15906MiB
`"""
th@debian:~$