Docs feedback: base64 command has an error 'invalid argument'

In this page I tryed to execute the base64 command on a MacOS and I got an error base64: invalid argument

base64 file.json | tr -decode \\n
tr: illegal option -- e
usage: tr [-Ccsu] string1 string2
       tr [-Ccu] -d string1
       tr [-Ccu] -s string1
       tr [-Ccu] -ds string1 string2
base64: invalid argument cpatachia-869737dd-39320d8489e8.json
Usage:	base64 [-hDd] [-b num] [-i in_file] [-o out_file]
  -h, --help     display this message
  -Dd, --decode   decodes input
  -b, --break    break encoded string into num character lines
  -i, --input    input file (default: "-" for stdin)
  -o, --output   output file (default: "-" for stdout)