Hi, @LemiKg. There is no way to delete a registered domain. We can transfer it to your direct control at the registrar to allow you to use the domain outside of Netlify or to transfer it to a different registrar.
I’ve created a support ticket and emailed you the instructions to transfer the domain to you. Please reply to the support ticket. However, if you don’t see the support ticket email, please do reply here to let us know.