Woocommerce REST API: Add meta data to line-item and to the database

I am building an ionic app with Woocommerce as backend.

I have seen some stackoverflow questions on this but they are actually not answering the question so I am raising this again.

I have been able to send order to the database but I need to add one more meta to the database and this data is the most important.

According to this woocommerce doc, the meta property is readonly hence not usable.

I want to know how I can achieve this either by adding extra parameter to the order line_item or by some wordpress or web hook.

I am using a JS implementation with WooCommerce API V3.