Change registration period after first transaction

Hello,

I initiated an ETH domain registration. I selected 2 years registration period and want to change it. I already did the first transaction.

Is it possible to change the registration period after the first transaction and how?
Is there a way to cancel the registration and restart it?

Otherwise it seems that the registration will automatically be canceled if the 2nd transaction is not completed within 7 days after the 1st transaction.

Thank you,

Philip

Anyone has an idea if that is possible and how?