Follow the instruction in page Create New Entity.
At Entity Status field in the Characterization section, make sure you select Pending as its status.
This will automatically make the page to ignore the fields for Company Registration Number (new), Company Registration Number (old) and Company Incorporation Date.
Hence, it will allow you to save this new Entity until you perform its incorporation with SSM via MyCoID system. Once you get this entity Incorporation Date, its Company Registration Number, you can enter them into their respective fields. Then click Save.