There are a couple of tables you can use datamodel to enter a query to select * from hrt_certification_items_v then look at the sample data. The link below is the guide for the tables. there are a couple of tables for the profile data where the certification is stored.…

Above the Licenses and Certifications folder there is the "All Profile Content" folder. I've found our license/certificate numbers also in the "ItemText2402" and "ItemText2403" has the license/certificate name

Did you try the folder named "Person Profile" in that subject area? There is a "Licenses and Certifications" subfolder with "Certificate Number" to choose .