Once logged in on GTIN.cloud, click on the "Assign New Product" button.
Once you've entered the information, you'd click on the 'save' button.
If the required fields are entered (product description and brand name), you'd see a 'request validation' option appear on the left menu (see below for an example). This button will also contain a purple circle to indicate how many UPC/GTINs are being requested validation. If you're needing more UPCs to be validation than the number indicates, you'd need to review the GTINs under 'Manage GTINs' to see if one or more is not in 'data entered' status.
After clicking on the 'request validation' button, your direct consultant (assigned after your GTIN support purchase) will email you regarding your next steps, either the steps on how to publish your GTIN or if any questions they may have regarding the entered information.