During Project creation through API, it is now possible to specify a template project id as optional. This will create a new project and copy the project settings and templates to the newly created project. Note: Field is the only service that supports templates today. As an additional check, there is a new API endpoint to confirm if the templates were copied successfully.
For more details, review the Post projects api and the new template_project_id parameter
POST projects – Create a new BIM 360 project in a specific BIM 360 account