To become a Cloud Architect from a Project Management background, you need skills in cloud computing, architecture design, security, automation, project management methodologies, communication, and aligning business requirements with cloud solutions.
If you are interested in pursuing a career as a cloud architect then I recommend you to take up this cloud and devops certification from Intellipaat. Along with that do check out this video of Kshitij Saxena about how he became a cloud architect after taking course from Intellipaat.