The Name & Number module is part of Fancy Product Designer Plus Add-On.
Via modules tab in the UI & Layout Composer you can add the names & numbers module to the product designer.
Define text or number placeholders
You also need to enable a text element as placeholder for a text (name) and/or number in the product builder.
For a number placeholder you can also define a range of allowed numbers. You can only define one text and one number placeholder in a single view.
In the plus tab of the global or individual product settings you are able to set the values for the dropdown and an additional price for every entry.