Hello arttemoff78
Thanks for your post.
Not sure how to achieve this. Maybe you can try to disable the Manage Stock in the Product Data tab, then you will be able to set your product In Stock.
Please, note that if you disable the Manage Stock, you will not be able to control the amount of stock.
However, if this doesn't help, I’d kindly suggest you get in touch with the WooCommerce Support Team, as ATUM is not related to this function.
Best regards,
Iryna