Add costs for shipping for local pickup

[roy-pon]

We use local pickup for multiple stores, these stores are partners of us. We enabled pickup for online orders but it is not possible to add shipping costs for local pickups, which is needed as we still need to ship the bike to those partner.

The challenge is that we have a headless setup and we are only using the checkout from Shopify. And in the checkout the user makes the decision on how they want to ship the products, via delivery or pickup. So we are limited on the options we can use.

We already tried a lot of things, but hopefully we are missing something. We are open to think outside-the box.
For example we tried to add a product via checkout.liquid to our checkout when the users selects local pickup, but this looks to be blocked by Shopify. We have also tried several script options, but neither seems to be meeting our requirements of adding a delivery price.