Dev really should fix that no reason you can't extend, Real-debrid and others let you add to your current sub to extend it.

You have to wait until your existing key expires. Then you’ll be able to enter the new one

I need help  I bought two Syncler plus keys earlier today from the premium keystore and have yet to receive the can anyone here please help me.

I have received a key from the approved reseller list, now I'm trying to use it to extend my license. Instructions say to activate under Manage but the only option there is Copy. How do I enter my key?

Key activation