Use product variant images as image swatches in Shopify store

1. From the app admin page, click Options
2. On the Option column, find the option you want to show as dropdown list
3. From Display style of this option, select Automated variant image swatch
4. Click Save to apply the changes

Upload variant image for swatch

This setting Automated variant image swatch will take data from the variant image on the Shopify product admin page → Please upload an image for each variant of the product

Here is the result you will see

Note: this function is limited in the Free plan, for your reference https://globo.io/kb/what-difference-of-the-plans-free-and-silver-and-gold/