Custom fields – variants

Hey,

I’m facing a challenge when I want to filter products on export when imported with a certain xml file. I have added a custom field on the normal import settings to know from which file this product came from. Let’s call this custom field ‘XX_ID’. I can filter the export by checking if this property is not empty and that works fine.
The problem comes with variations. I can’t seem to find a way to add a custom field on the variants, with the standard version of Wpallimport. I tried adding it with update_post_meta, but nothing happens. Is this a feature only on the pro version?

Another thing I tried was to find the parent product of the variation and trying to check if the parent product has this custom field filled in. I am able to get the parent product but can’t seem to find the value of the custom field again. Tried it with get_post_meta but again, didn’t get anything back from that. So is there another way to get the custom field value on the function editor?

If there’s other ways that you could think to go around this problem, please share!