You have set up your Variant Tagger rule, but products didn't get the associated tags added? Let's go through the most common things to check:

In case you have just set up the Variant Tagger rule or edited the settings, the job could be still in a queue or running. The time to complete the update depends on the number of products that are to be tagged (due to the Shopify rate-limiting API our app processes around 2 products per second).

The app will also update the tags based on the variant's availability during the store updates which are being run every hour or so.

While setting up a Variant Tagger rule the first field you need to fill in the 'Variant option title':

This text should match exactly the variant option title you have in your Shopify admin for a product:

In case you have a variant option titled 'Choose a Color' or 'Available Colors' in your Shopify admin, use this text as the title for your Variant Tagger rule.

If you enable the app to 'Exclude sold out variants', variants should have inventory and be available for purchase at the 'Online Store' channel. The app will only tag products based on variants that are in stock and remove the tags when certain variants are sold out.