Get a list of all manually installed packages using apt

get-all-manually-installed-apt.sh

#!/usr/bin/env bash

cat /var/log/apt/history.log 2>/dev/null |
  egrep '^(Start-Date:|Commandline:)' |
  grep -v aptdaemon |
  egrep '^Commandline:'|rg 'apt install'|sed 's/Commandline: apt install//'
  
# Last tested on ubuntu 22.04 (29/12/2022)

:)

following should be the correct and more appropriate command. ( In your cmdline, 'rg' has no meaning and it may give duplicates as well, plus the log files rotates therefore the archives logs should also be considered. )

zcat /var/log/apt/history.log.*.gz | egrep '^(Start-Date:|Commandline:)' | grep -v aptdaemon | grep 'apt install' | sed 's/Commandline: apt install//' | tr ' ' '\n' | sort -u