Answers for "ubuntu downgrade php 8.1 to 7.4"

ubuntu update php 7.4 to 8

sudo apt-get purge php7.*
# recommended 
sudo apt-get autoclean
sudo apt-get autoremove
sudo add-apt-repository ppa:ondrej/php
sudo apt-get update
# end recommended 
sudo apt-get install php8.0

brew downgrade php 8 to 7.4

$ brew unlink [email protected]
$ brew link [email protected] --force --overwrite