Custom Tab Title and Custom Tab Content

[cgaeking]

While creating or updating a product with this api it seems not to be possible to add data to Custom Tab Title and Custom Tab Content.
Visible at Extras-Tab of a product.

I tried to set it unter meta_data with:
key=> "wc_productdata_options",
value => [ "_custom_tab" : "My tab content", "_custom_tab_title": "My Tab" ]

But that did not work.