I'm talking about the MS-Project Online ODATA-Feed, described e.g. here: https://learn.microsoft.com/de-de/previous-versions/office/project-odata/jj163015(v=office.15) I can't find any information if the ODATA-Feed supports Create, update or delete operations? There are only read examples in the internet for the MS-project-odata-API.
I've found the answer myself now. MS Project hast two odata-APIs, the one I used before was _api/ProjectData. Use _api/ProjectServer instead and cud-operations are possible. The endpoints and thus the data you get is very different as well. Here is the documentation link: https://learn.microsoft.com/en-us/previous-versions/office/project-javascript-api/jj712612(v=office.15)