using Microsoft.Online.SharePoint.TenantAdministration; using Microsoft.SharePoint.Client; namespace SharepointToolbox.Services; public class OwnershipElevationService : IOwnershipElevationService { public async Task ElevateAsync(ClientContext tenantAdminCtx, string siteUrl, string loginName, CancellationToken ct) { var tenant = new Tenant(tenantAdminCtx); tenant.SetSiteAdmin(siteUrl, loginName, isSiteAdmin: true); await tenantAdminCtx.ExecuteQueryAsync(); } }