Can I configure the app to show only products with the same tag?

Yes, you can limit the random recommendations displayed to products with the same tag of the current product.

Just go to the Shopify admin sidebar, on the Apps > Frequently Bought > Recommendation tuning page, go to the Types of recommendations section and click on the Configure button for Random recommendations:

Select the Filter by product tag option (random recommendations must be enabled as shown in the previous screenshot):

Let's say, for example, that you are viewing a product page of a product with the tag Woman. The random recommendations displayed will only be products with the Woman tag.

Please note that, if there are not enough products matching the selected criteria, the recommendations will be automatically completed using random recommendations.

Please note as well that app utility tags, such as Global recommendation, Hidden recommendation or Recommendations disabled, are not taken into account when generating random recommendations by tag.