Does Shopify handle self-referencing hreflang tags automatically?

[Jockbox]

Hey, I’ve recently upgraded to the Shopify Plan so that I can add a .US domain, but on SEMrush, it’s showing that 37 pages have no self referencing hreflang tags, but shopify is supposed to handle this right? 

Thanks,

the site is jockbox.co.uk

[Samphire]

following - same issue 

[Ben1000]

Following