1 - Create new branch from master
git checkout -b cloud/upgrade-2.4.5
2 - Push that branch to cloud
git push -u cloud cloud/upgrade-2.4.5:upgrade-2.4.5
3 - Set that branch to the environment with parent staging
magento-cloud environment:info -e upgrade-2.4.5 parent staging
4 - Ative o environment
magento-cloud environment:activate -e upgrade-2.4.5
5 - List your environments
magento-cloud environment:list