How do i get shipping methods on the checkout page from an api

I’m trying to create a plugin similar to a woocommerce and a magento plugin i’ve already created. the main goal of the plugin is to get shipping options from our platform and show them on the checkout page.
I cant find any documentation on how to do this in shopware. The only thing that comes close is the payment method plugin example. the problem with this example is that the options are being added when installing. I need to be able to show the shipping options on request in the checkout. Is this even possible in shopware, and if so. can anyone help me in the right direction?