Jungs, helft mir

There is a key that opens this kind of window. It has a handle in the end, similar to normal window or door handles.
Something like this
[window opener](https://www.puuilo.fi/pisla-ikkuna-avain-paula-samakki-kromattu?srsltid=AfmBOopSmlj4cZyAs5ZQEMyXyJnvNztmbwvT4jQCRozT4iCx_ACAraYC)

Edit: added link

https://www.puuilo.fi/pisla-ikkuna-avain-paula-samakki-kromattu?srsltid=AfmBOoqctnc_fPEjL4CgzY_GT0oADXxAH5-mSubITQmzRriXuQPX8XBELjY you need to get/find something like this in the link.

Normally you can find this window opener / key from the apartment. You should check the cleaning closet if it’s there.

After you get the key, you insert it to the round metal thing and turn it 90 degrees. You need to try to witch direction will the lock rotate.

You can also use a large flat head screwdriver