I have been following this guide for setting up my app as a fulfillment service
https://shopify.dev/docs/apps/build/orders-fulfillment/fulfillment-service-apps/build-for-fulfillment-services
I find one key point missing; How can I pass X-Shopify-Access-Token header to the api to the following endpoints to make authenticated calls to request and update relevant information?
GET: https://${shopDomain}/admin/api/2024-04/assigned_fulfillment_orders.json
POST: https://${shopDomain}/admin/api/2024-04/fulfillment_orders/${fulfillmentOrderId}/fulfillment_request/accept.json
POST: https://${shopDomain}/admin/api/2024-04/fulfillments.json
Since the user is not actively using the app the access token would not be available correct?
The token expires after 24 hours and even if it is stored on our server how would our server have authorized access after that?