ok, try to make a prototype creating Tasks in planner from ASP.NET webforms this is really hard at the moment stuck in Graph explorer error Message https://graph.microsoft.com/v1.0/planner/plans/Frczk8wfmEGL--------------- permissions for graph explorer set (User.Readwriteall. Groups.Readwriteall)
got to tasks.office.com select plan and read planid form uri (is this really the way how it works?)
trying the samples in Graph Explorer and get a tipp to got to Stackoverflow
just right now also https://graph.microsoft.com/v1.0/me/ doesnt work (worked sometimes before)