The Bulk-Add Variations Form is part of Fancy Product Designer Plus Add-On.
Go to the Plus tab in the global or individual product settings, there you need to define the placement of the form. After that define the variations, first you define the name of the select dropdown e.g. Size followed by a "=", then you define the option values separated by "|", e.g. Size=M|L. If you want to add more select dropdowns, you need end a select group with ";".
Example