Found how to do it in my personal o2 account
Another question is what if I’ll not transfer my number in this 30 days period
Will it stay in o2 and  coninue working?

@Vienn1 you pay now only 6,82 Euro for take away your number from o2. If you don’t transfer your number you stay at o2. I think you have a prepaid tariff. Set the Opt-in option for this type only over hotline or here over an o2 moderator.

Hi @Vienn1, 

welcome to our English community. 

As I can see, you already have cancelled your contract. Your contract will therefore end on 3rd December 2020. 

I also can see that we already released your number. Therefore, please contact your new provider in order to ask for the immediate porting of your number to the new provider. 

As soon as we get an order from your new provider about the transfer of your number, we will change your number automatically to a new o2 number. You will be able to use the new number until the deactivation date. 

As @Joe Doe already told you, we will charge you with 6,82 € for the porting of your number to the new provider. 

I hope that this information is of help to you. 

Loving greetings,

Tobias