Although the customer’s user has all the necessary privileges assigned in the Admin Console, including Admin rights, whenever trying to create a new project from AEM Start - Projects - Create - Project there is no project template available hence, no project can be created.
According to 1, AEM ships with three different templates out of the box:
However, the customer can see none of these templates.
1 https://experienceleague.adobe.com/docs/experience-manager-cloud-service/content/sites/authoring/projects/overview.html?lang=en#project-templates
For the project templates to be visible in AEM, the property - cq:allowedTemplates of type String and the value /(apps|libs)/.*/projects/templates/.</b>* must be present under /content/projects/jcr:content.
It was found that the issue was caused by the fact that the customer had no jcr:content node under /content/projects. After creating the jcr:content node and adding the cq:allowedTemplates attribute the customer could see all three project templates.