I used to not need "-i" when using base64

I am using macOs 13.6.1 (22G313) for a machine. I used to be able to base64 a .p12 file (maybe 1 - 3 years ago) using the following format from the terminal: base64 mastercard-track.p12 > mastercard-track_base64.txt Now when I attempt to use the base64 program like that, I get this error: base64: invalid argument mastercard-track.p12 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) Is the base64 program I used to use different now?