How can I apply discount code over total order amount but without considering products tagged with “no-discount” tag (for example)
Let’s suppose in this case first product (the red one) has “no-discount” tag.
If I apply a discount code, first product’s price won’t be affected by it, but the rest of then will be.
I don’t think there’s a way to do that unless you build a custom app or have Shopify Plus.
You can choose the products / collections in the Discount section in Shopify. Maybe you could adjust your workflow to exclude them there instead of by tag. More info here: https://help.shopify.com/en/manual/discounts/discount-types
