How to use “gla_”+product_id as MPN?

Hello @demixo,

Thank you for reaching out!

You can simply link the MPN to a product attribute field. :?)

Link to image: https://d.pr/i/JsngDm

For more context, kindly check: https://woo.com/document/google-listings-and-ads/#global-attribute-mapping

For a more dynamic option, you can work with the woocommerce_gla_product_attribute_values filter.

add_filter( 'woocommerce_gla_product_attribute_values', 'woocommerce_add_MPN_prefix' ,10,3 );

function woocommerce_add_MPN_prefix( $attributes, $wc_product, $gla_product ) {
      return [ 'MPN' => 'gla_' . $wc_product->get_id() ];
}
}

Kindly note the snippet above is just pseudo code (not tested). If you require the assistance of a developer, consider hiring a WooExpert. :?)

Let us know if you have any other questions!