About creating custom fields

I’m using Crocoblock’s Jet Engine.

I’d like to use WP Import Export to assign items from a spreadsheet to metafields (custom fields) and create and post multiple articles at once.

However, the names (slugs) I set for the metafields don’t appear in the custom field items. (I’m using the free version.) I’d like to know if Jet’s metafields are only available in the paid version, or are Jet Engine’s metafields not available?

I don’t want to import everything in WP.

I just want to post the information from the spreadsheet in bulk. In that case, I need to assign items to metafields.