string[] projs = new string[] { "CT22-0029", "CT22-0031" };

            foreach (var projName in projs)
            {
                var subProjSite = siteOptions.GetSubProjSite(projName);
                var ctx = authenticationManager.GetContext(subProjSite);

                var docLibName = $"Commerciale {projName}";

                var web = ctx.Web;
                var list = web.Lists.GetByTitle(docLibName);
                ctx.Load(list);

                list.BreakRoleInheritance(false, true);
                ctx.ExecuteQuery();

                var adGroup = web.EnsureUser("accounting@italsortbuttrio.onmicrosoft.com");
                ctx.Load(adGroup);

                var roleD = web.RoleDefinitions.GetByName("Contribute");
                var roleDb = new RoleDefinitionBindingCollection(ctx) { roleD };

                list.RoleAssignments.Add(adGroup, roleDb);
                list.Update();
                ctx.ExecuteQuery();

                Console.WriteLine($"Done for {projName}");
            }