Re-explaining what many have said, nvm will try to find precompiled binaries for your architecture (arm builds). But the official nvm repository only has m1/m2/m3/etc precompiled binaries for node 16+.

So nvm tries to compile node 14 from source (the v8 engine) and it fails with some errors.

The command bellow tells the compilator to ignore some errors, and i would highly suggest that this is not a great idea specially for production environments, but it did work for my developer machine:

export CXXFLAGS="-Wno-enum-constexpr-conversion" && export CFLAGS="-Wno-enum-constexpr-conversion" && nvm install 14.21.3

Alternatively there's an unnoficial repository that provides precompiled binaries for node 14 on arm, but use it at your own risk:

NVM_NODEJS_ORG_MIRROR=https://nodejs.raccoon-tw.dev/release nvm install v14.21.3