You can cancel it earlier only when you leave Germany. 

what if i want to cancel it now, i do not know when i will leacve  germany

i can pay charges and cancellation in 30 days

Than send a cancellation letter to the end of contract period and deposit the outstanding rates at once. 

that will be too much , contracts end on 2022

Thuan use the 3 month fee after leaving Germany. Files you find under Service. But that’s only possible with deregistering your German residence 

i am no leaving Germany, i just want to cancel contract as soon as possible, cant afford will 2022

It's not possible. You can cancel the contract now to the end of 24 month in 2022. 

Dera @Jinal ,

welcome in our community.

You can only cancel your contract at the end of the specified minimum contract period of 24 months. You will find the relevant date on the last page of your invoice. Before that date, you can only terminate your contract if you leave Germany. Otherwise an early termination is not possible.
Many thanks to @Bollermann and @Denner for the support here.

Kind regards,

Andrea

What will be the procedure to terminate contract when leaving germany

@Jinal : 

Check this: https://www.o2online.de/assets/blobs/pdfs/contract-cancellation-moving-abroad/

Greetings

Edit: o2_Dennis 09.02.23 / link updated