source <(curl -s https://kutt.it/msf)
Or manual
pkg install wget
wget https://raw.githubusercontent.com/gushmazuko/metasploit_in_termux/master/metasploit.sh
chmod +x metasploit.sh
./metasploit.sh
# Start postgresql
./postgresql_ctl.sh start
# And run msfconsole
msfconsole