We have a mutlivendor ecommerce platform and we need it to be able to charge a single delivery fee when all items are bought from a single vendor and extra fee when buying from multiple vendors in the same cart

We are looking for an experienced developer to help us make a specific modification to our existing Laravel-based ecommerce platform. We currently have multiple vendors selling on our platform, but we need the system to be able to charge a single delivery fee when all items are purchased from a single vendor and give an additional fee when multiple vendors are involved in an order. We are also using multiple payment gateways for payments, so these must be integrated into the changes. If you have the experience and skills to help us make this change, please do not hesitate to get in touch and we can discuss the details further. Thank you!