From what I remembered, this is the rule.
If you did not sign up using a promo code, I think you still have a chance to sign up another account. To move your domain name between the two accounts, you have to contact DH support.
If you already used a promo code to sign up your account, you can’t register the same domain name in other accounts.
I’ll suggest you to contact DH support via DH panel --> Support --> Contact Support
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