If you are importing products from CSV as described in https://docs.woocommerce.com/document/importing-woocommerce-sample-data/, i.e. by using the standard “WooCommerce products (CSV)” tool, then you need to add
"Meta: _alg_msrp" column to your CSV file. If you are using some other tool for importing then you probably need to set somewhere for the column to import to meta with
Hope that helps. Please let me know if you have any questions.
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