Wix Stores Customizing the "Out of Stock" Button

Currently, it is not possible to customize the design of the "Out of Stock"
button.

Update:

You can now edit the text of the "Out of Stock" button.

We are always working to update and improve our products, and your feedback is
greatly appreciated.

If this is a feature you would like to see in the future, please click Vote
for this feature and we'll make sure to keep you updated.