Hello Reader,

The following code is used to create a new Enterprise Project Type(EPT):

public void CreateEnterpriseProjectType(Guid eptGuid, string eptName, string eptDescription)
    {
        ProjectContext projectContext = new ProjectContext("http://serverName/pwaName");
        // for project online authentication
        SecureString securePassword = new SecureString();
        foreach (char ch in "adminPassword")
            securePassword.AppendChar(ch);
       
        SharePointOnlineCredentials sharePointOnlineCredentials = new SharePointOnlineCredentials("adminUsername", securePassword);

        projectContext.Credentials = sharePointOnlineCredentials;

        projectContext.Load(projectContext.EnterpriseProjectTypes);
        projectContext.Load(projectContext.ProjectDetailPages);
        projectContext.ExecuteQuery();

        EnterpriseProjectTypeCreationInformation eptInfo = new EnterpriseProjectTypeCreationInformation();


        eptInfo.Id = eptGuid;
        eptInfo.Name = eptName;
        eptInfo.Description = eptDescription;
        eptInfo.IsDefault = true;
        eptInfo.WorkspaceTemplateName = "PROJECTSITE#0";
        eptInfo.ProjectPlanTemplateId = Guid.Empty;
        eptInfo.WorkflowAssociationId = Guid.Empty;
        eptInfo.Order = 1;

        List<ProjectDetailPageCreationInformation> projectDetailPages = new List<ProjectDetailPageCreationInformation>() {new ProjectDetailPageCreationInformation() { Id = projectContext.ProjectDetailPages[1].Id, IsCreate = false }};
        eptData.ProjectDetailPages = projectDetailPages;

        EnterpriseProjectType newEpt = projectContext.EnterpriseProjectTypes.Add(eptInfo);
        projectContext.EnterpriseProjectTypes.Update();
        projectContext.ExecuteQuery();
    }

I hope, it helps.