The Shopify Default Currency is usually "30.00", etc. Please concentrate on its type, which is 00.00, you can change it to 0, Rounded decimal Odd decimals, etc.
To change it, please follow this official guide from Shopify.
Usually, Shopify support will always say to contact the theme owner, but actually, it depends on the Shopify dashboard configuration, not the theme side. Here are the steps:
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