The current iteration of Qlik Cloud is limited in scope to only allow for uploading and creating applications in Qlik Sense Cloud as well as loading excel based data. You cannot currently manage the environment, such as creating/managing security rules or adding/removing extensions. This may change in the future.
If you would like to share application with other users in a managed environment, you could deploy Qlik Sense Enterprise within your own data center or in a hosted environment such as AWS or Azure. In this way, you can have a full fledged Qlik Sense deployment with all the flexibility in managing and governing the environment in a way that best fits with your requirements.