You can order up to three items from our online shop and we can keep them here for up to one week.
この場合、次のような言い方ができます。
ーYou can order up to three items from our online shop and we can keep them at our store for up to one week.
「当店のオンラインショップから3点まで取り寄せることができ、当店舗で1週間までお取り置きできます」
to order up to three items「3点まで取り寄せる」
to keep ... for up to one week で「…を1週間まで取り置く」
ご参考まで!
You can order up to three items to the store. We will hold them for one week.
You can order up to three items to the store. We will hold them for one week.
・You can order up to three items to the store.
「店舗へのお取り寄せは合計3点まで可能です」
up to は「~まで(最大で)」という意味で、上限を伝える際によく使われます。