Change CRS of a WebMapServiceImageryProvider

Hello everybody,

I´m currently working on a project where I need to embed a WMS, which doesn´t support CRS:84 but many EPSG Versions. Here is the link to the WMS, which I need to include (the service is not controlled from our side).

I hope that someone around here could help me to change the CRS in my cesium project.

I´m happy for any help.