$ cd /somewhere/ $ unzip mafft-7.490-mac.zip
$ cd /somewhere/ $ ls -F mafft-mac/ $ cd mafft-mac/ $ ls -F mafft.bat* mafftdir/
% /somewhere/mafft-mac/mafft.bat input.txt > output.txt
% /somewhere/mafft-mac/mafft.bat --localpair --maxiterate 100 input.txt > output.txt
Try this only when the command-line mode is not useful.
% cp input.txt /somewhere/mafft-mac
% cd /somewhere/mafft-mac
% ./mafft.bat --------------------------------------------------------------------- MAFFT v7.490 (2021/Oct/30) MBE 30:772-780 (2013), NAR 30:3059-3066 (2002) https://mafft.cbrc.jp/alignment/software/ --------------------------------------------------------------------- Input file? (FASTA format; Folder=/somewhare/mafft-mac) @ input.txt