On 31 May 2023, WooCommerce retired the WooCommerce Follow-Ups extension and they recommend that customers use AutomateWoo instead. As such, WooCommerce Follow-ups is no longer available for purchase on the WooCommerce Marketplace. WooCommerce will continue to support the WooCommerce Follow-ups extension until May 2024, however, it appears that no further plugin updates will be released.
We have implemented a similar integration with AutomateWoo which we recommend as an alternative solution