use @zeit/fetch server-side

lib/bigcommerce/api/utils/fetch-graphql-api.ts

@@ -1,7 +1,8 @@
 import { FetcherError } from '@lib/commerce/utils/errors'
-import type { GraphQLFetcher } from 'lib/commerce/api'
+import type { GraphQLFetcher } from '@lib/commerce/api'
 import { getConfig } from '..'
 import log from '@lib/logger'
+import fetch from '@lib/fetch'
 
 const fetchGraphqlApi: GraphQLFetcher = async (
   query: string,

lib/bigcommerce/api/utils/fetch-store-api.ts

@@ -1,5 +1,6 @@
 import { getConfig } from '..'
 import { BigcommerceApiError, BigcommerceNetworkError } from './errors'
+import fetch from '@lib/fetch'
 
 export default async function fetchStoreApi<T>(
   endpoint: string,

lib/fetch.ts

@@ -0,0 +1,3 @@
+import zeitFetch from '@zeit/fetch'
+
+export default typeof window === 'undefined' ? zeitFetch() : fetch