The default PHP version in the Cloud Platform user interface is 8.3.
CHANGE
NW-10924
[Cloud Next] The OS version can be upgraded to Ubuntu 22.04 through the Cloud Platform user interface. For more information, visit Configuring OS versions.
Note
Currently, Ubuntu 22.04 is unavailable for FedRAMP applications.
Cloud Platform - October 13, 2024 | Acquia Product Documentation
Cloud Platform