How to Grey Out or Cross Out size that is unavailable

[SHIGHT_VAULT]

Please I want to Grey Out or Cross Out Sizes unavailable on my Shopify website so they dont need to click on the unavailable size before they see "out of stock" unclickable button. Pls anyone knows how I can do this? I have no idea of coding so pls If anyone could pls assist me as soon as possible. I'd really appreciate this.

[SHIGHT_VAULT]

Please, How can you help?

Is this something you can explain to me in details maybe I could do it with your steps?

[nalanetworks-]

Some themes include a toggle for this under the Product information or Variant picker section, but the Dawn base theme doesn’t offer that option by default — you’ll need to edit the code to add this functionality.