Answers for "how to update magento 4.3 version"

upgrade magento 2.4

php bin/magento maintenance:enable
composer require magento/product-community-edition=2.4.0 --no-update
composer update

php bin/magento setup:upgrade
php bin/magento setup:di:compile
php bin/magento setup:static-content:deploy -f
rm -rf var/cache/*
rm -rf var/page_cache/*
rm -rf generated/code/*
php bin/magento cache:clean
php bin/magento cache:flush