rsgain will do this--see the second option below. On the other hand the usage description is a head shrinker (
https://github.com/complexlogic/rsgain). Note that it can be used with a GUI when paired with a Musicbrainz Picard plugin. With MusicBee you could tie the command line option you want to an External Tools entry. Good luck
Custom Mode allows the user to specify the options to scan the files with. The
list of files to scan must be listed explicitly after the options.
Options:
-h, --help Show this help.
-a, --album Calculate album gain and peak. -S, --skip-existing Don't scan files with existing ReplayGain information.
-s s, --tagmode=s Scan files but don't write ReplayGain tags (default).
-s d, --tagmode=d Delete ReplayGain tags from files.
-s i, --tagmode=i Scan and write ReplayGain 2.0 tags to files.
-l n, --loudness=n Use n LUFS as target loudness (-30 ≤ n ≤ -5).
-c n, --clip-mode=n No clipping protection (default).
-c p, --clip-mode=p Clipping protection enabled for positive gain values only.
-c a, --clip-mode=a Clipping protection always enabled.
-m n, --max-peak=n Use max peak level n dB for clipping protection.
-t, --true-peak Use true peak for peak calculations.
-L, --lowercase Write lowercase tags (MP2/MP3/MP4/WMA/WAV/AIFF).
This is non-standard but sometimes needed.
-I keep, --id3v2-version=keep Keep file's existing ID3v2 version, 3 if none exists (default).
-I 3, --id3v2-version=3 Write ID3v2.3 tags to MP2/MP3/WAV/AIFF.
-I 4, --id3v2-version=4 Write ID3v2.4 tags to MP2/MP3/WAV/AIFF.
-o d, --opus-mode=d Write standard ReplayGain tags, clear header output gain (default).
-o r, --opus-mode=r Write R128_*_GAIN tags, clear header output gain.
-o s, --opus-mode=s Same as 'r', plus override target loudness to -23 LUFS.
-o t, --opus-mode=t Write track gain to header output gain.
-o a, --opus-mode=a Write album gain to header output gain.
-O, --output Output tab-delimited scan data to stdout.
-O s, --output=s Output with sep header (needed for Microsoft Excel compatibility).
-O a, --output=a Output with files sorted in alphanumeric order.
-q, --quiet Don't print scanning status messages.