0- durum nasil su an ? kim ne kullaniyor?
egrep php[1,2,3,4]_select= /usr/local/directadmin/data/users/*/domains/*.conf

1- once bir sey olmasin aman mevcut durumu yedekle
tar czvf ~/domain-conf-backup.tgz /usr/local/directadmin/data/users/**/domains/*.conf

2- Force PHP to be version 1 if no default is set
grep -rF -L php1_select /usr/local/directadmin/data/users/**/domains/*.conf | xargs sed -i.step1 '$ a php1_select=1'

3- /usr/local/directadmin/options duzenle diledigin gibi
cd /usr/local/directadmin/custombuild
./build set php1_release 8.0
./build set php3_release 7.4
./build php

4- Now you want to move all the users who used php1 to use php3, so, you execute this script:
#!/bin/sh
for i in `ls /usr/local/directadmin/data/users/*/domains/*.conf`; do
{
       if ! grep -q ^php1_select $i; then
               echo php1_select=3 >> $i
               continue
       fi

       perl -pi -e "s/^php1_select=1/php1_select=3/" $i
};
done
exit 0

5- Update config files:
cd /usr/local/directadmin/custombuild
./build update
./build rewrite_confs