coinbase.com – Coinbase API create new address returns 404 “not found”

I am trying to create a new address for my Coinbase account to try putting some coins in it with my application.
I am using .Net core for accessing the Coinbase endpoint.
I have tried both creating requests manually and using the NuGet package “Coinbase”, for casual requests like fetching user data, changing user data (nickname) everything is working fine (so the error is not in bad request creation or similar) except when I want to create a new address for putting some crypto in it. It returns not found. Also I tried fetching the list of addresses and it also returns 404 (I have plenty of addresses when I check my account under Settings/Crypto Addresses).
Do I miss some configuration on my Coinbase account? I am using the API key and API secret and I granted all permissions to it. I have linked that account to Coinbase wallet on my phone.
Thanks for the help.