Park domain error: This domain already in use

About 3 months ago I created a website and parked the domain fmkristal.com.ar
Due to some problems, I deleted the account, and registerd from scratch using the same email address.
But when I try to park the domain again it shows an “This domain already in use” error.
How can I retrieve the parked domain back? The 000webhost.com account is “fmkristal@hotmail.com” (https://fmkristal2.000webhostapp.com/).

Thanks in advance.

Unfortunately that domain won’t be able to be used again on the free learning service.
Feel free to upgrade to Hostinger to resolve this or you can use other free hosting if you really need that custom domain attached.