If you have activated DNSSEC, your provider World4you must create the DNSKEY RR, must create minimal one DS (the DS has some informations about the first DNSKEY) and must send the DS RR to the parent zone (the com zone).
So this (creating a DS and deploying it) isn't an additional step, it's a fundamental part (the last and critical step) activating DNSSEC.
But I don't understand your configuration.
Rechecking your domain now your DNSSEC is broken - https://check-your-website.server-daten.de/?q=12bfree.com
But your older check - 2019-10-30 had a valid DNSSEC configuration:
Both have the same DS - KeyTag 40397, DigestType 2, Digest "xRUDH/3tAN/+INF2VlTJUmszJrkpOLtzk7UulszuAAg=".
But the local DNSKEY is new - not KeyTag 40397, instead a KeyTag 2371.
So now your DNSSEC is broken. And the system of your hoster is terrible -> switch to another hoster, that's bad.
Correct DNSSEC: New local DNSKEY created + new DS key created and sent to the parent zone (one step).
PS: That's
not possible. Why do you want to edit DNSSEC manual? DNSSEC has nothing to do with another DNS provider.