1. Install WINE
uname -mrs
Output should look something like FreeBSD 12.1-RELEASE-p1 amd64.
pkg install -y wine wine-devel wine-staging
pkg install -y i386-wine i386-wine-devel i386-wine-staging
Why does these packages have i386 as prefix for 64-bit FreeBSD?
These packages are only meant to allow 32-bit wine on amd64 systems. If you're on 32-bit FreeBSD, these packages have a failsafe that redirects to 32-bit packages.Although FreeBSD can build and run the pure 64-bit version of wine it still doesn't support WoW64 which is necessary for the overwhelming majority of Windows apps, AMD64 systems still need to use the 32-bit package.
1.2. Install
First,
pkg install -y wine-gecko wine-mono wine
alternatively
pkg install -y wine-gecko-devel wine-mono-devel wine-devel
Then, as a normal user (not root)
/usr/local/share/wine/pkg32.sh install wine mesa-dri
wine setup.exe
wine control
wine uninstaller
2.4. Example with Zotero
wine Zotero-x-y-z.exe
Note that this should install/work even without accepting the prompts to install wine-mono and wine-gecko.