Multiscrape Fritz!Box

I would like to read the MyFritz (myfritz.box) page using multiscrape. A SID is required for dialing in. A session was started and attempts to read out the data via the valid SID. Unfortunately it wasn’t possible. When you try to log in using the submit form, you are only informed that no form could be identified. How can I read the page using multiscrape?