Export Custom attributes in babylon

While Exporting the babylon file added extera attributes to meshes but when exported metadata says null.
Tried doing it with mel script provided it throws a error

// Error: line 1: Cannot find procedure “GenerateExportersParameter”. //

need some help on this

Hello and welcome, can you tell us from which DCC tool you are exporting and ideally adding a link to a sample file?

Adding @Drigax

We are using Maya for for designing. Adding up the demo file with extra attributes.

I have followed this tutorial :

PS: Kindly point me in a right direction…

Any updates is there any possibilities that we can a meta data from maya??