How can I calculate shipping price through my own API?

Shopify Apps
,
1

Hello, when creating an order, I need to calculate the shipping price according to my logic, through my api, how can I do this?

2

Checkout Carrier Calculated Shipping (CCS) in Shopify
https://shopify.dev/docs/api/admin-rest/2023-01/resources/carrierservice

3 
# Shipping lines format
shipping_lines = [{
  title: your_shipping_title,
  price: your_shipping_line_price,
  code: your_shipping_code,
  source: your_shipping_line_source
}]

# Example
shipping_lines = [{
  title: "Standard Shipping",
  price: 10.0, # if you want free shipping, you can set this as 0
  code: "Standard Shipping",
  source: "shopify"
}]

# Create order using Shopify API
payload = {
  # other fields
  shipping_lines: shipping_lines
}

ShopifyAPI::Order.create(payload)
4

That is, I create an endpoint (I accept it), I process everything and give the response, will this be taken into account when ordering an order and during checkout?

5

Yes. Exactly.
Be mindful that you need CCS to be enabled on your store for this to work.
Check this document on how you can get CCS activated: https://help.shopify.com/en/manual/shipping/setting-up-and-managing-your-shipping/enabling-shipping-carriers