Rewriting the Woocomerce wordpress plugin

I will commission a rewrite of the Conotoxia Pay payment plugin integrated with our WooCoomerce store.

Unfortunately, a huge drawback of this plugin is the functionality of making payments by moving the payment window outside the store (in this case to Cinkciarz), and we would like the payment to be made inside our store.

We would like the plugin to be integrated so that the customer can choose to pay via Visa, Mastercard, Vipps, or Trustly (the operators we have selected in the plugin ), and then be guided through the payment exclusively on our online store.

Cinkciarz provides documentation with which to perform Integrations: (https://docs.cinkciarz.pl/platnosci/integrator).

I would very much appreciate an approximate amount for the realization of the project and possibly the time of implementation. We have a test environment to check the operation of the plug-in.