How do I set a catchall email address with iCloud Mail+?

I have added all the DNS records required for using the Apple's MX server but when I try to send an email to the address, it is rejected with the following message:

This is a system-generated message to inform you that your email could not
be delivered to one or more recipients. Details of the email and the error are as follows:
 
<[email protected]>: host mx01.mail.icloud.com[17.57.152.9] said: 550 5.1.1
<[email protected]>: user does not exists (in reply to RCPT TO command)

Is there no way to add catchall email addresses (addresses that catch all emails sent to *@domain.tld) to iCloud Mail+?

Presently, the settings page says the following:

Currently no. The Custom Email Domain feature of iCloud+ is currently a beta service. Since the service is still being tested, it does not allow 2 letter email ids. And, it currently only allows 3 custom email ids to be created per domain and per member (if you've enabled it for family too). So catch all emails to your domain on iCloud+ will definitely not be possible right now, as otherwise, there wouldn't be a limit of 3 email ids per domain per member.