I just pkg installed node12-12.13.1 and npm-node12-6.12.1 on FreeBSD 12.1p3 and neither would run because libuv was apparently not a required package.
After pkg install libuv-1.34.0, both node and npm function normally.
libuv needs to be added as a prerequisite to both packages.
www/node12 already has libuv as a dependency.
I'm 0 for 2 today :-( Maybe I was on a back level of libuv. I needed to upgrade to libuv 1.34.
Perhaps the dependency has the wrong libuv version?