After paying monthly subscription re-install is asking for payment again
When you uninstalled the app, your monthly subscription was cancelled so Shopify is asking you to accept again the recurring charge associated to the app subscription. This happens even if you uninstalled the app one minute ago because your recurring charge was cancelled.
Please note that payments are managed directly by Shopify. It is Shopify, not us, who charges you, and then transfers our part to us. You can contact Shopify support for any question related to the app charges.