How to switch to Fiber optics

Hi Team,

Few weeks before Fiber optics connections was installed at my home Schiermonnikoog 28, Zaandam
and I can also see on Tmobile website that Fiber is available at my home.

I already have Tmobile House subscription(wired) and I want to switch to Fiber for that. So just want to know what i need to do for the same?
 

Thanks,
Tarun