Greetings and welcome! Did you create an Adguard account on the main site? If so log into it and you can manage your license(s) there - you can deactivate the old phone allowing you to reuse your license on the new phone.
@Boo Berry pretty much answered the question. I can only add that you can simply reset the license on your current phone right from the app menu, and you will be able to activate it on any other (or the same one) phone immediately.
It is now me to change the Android phone, and I would like to transfer the existing Adguard license to the new device.
I am aware that, using the personal Adguard account, one can release a license from an old device to be able to assign it to a new one.
I have browsed the Android Discussion forum for license related topics, and have read them. I have also read the knowledge base article on the Adguard license key, and it tells me the same as this topic does.
However, while I own two 2-device (PC + Android) Adguard Lifetime licenses, my Adguard account does not list any Android Smartphones but only the PCs, so it will just allow to release the license from the PCs. But I want to keep my PCs and replace a Smartphone.
So how do I transfer an Adguard Android license in this constellation please? Release the license from a PC, then reassign it back to same PC and also assign to new Smartphone?