To add HREFLANG Tags on each product page, select the “Product” box on the HREFLANG Settings screen:
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The meta boxes for entering the tags will then appear at the very bottom of each product page.
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The second step is to configure the shop pages.
Click into the Woocommerce/Shop tab:
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This tab is useful if the Shop page is a part of your template and doesn’t have an editable page in the dashboard. You can enter all the alternative URLs for your shop page here and save.