Can I use an App Store Gift Card towards my purchase of a MacBook Pro?

No, that gift card is only good in the iTues associated stores.

ASC - Late 2012 Mac mini, macOS 10.14;  Watch, series 3 cellular, watchOS 5; iPad Air 2 & iPhone 8+, iOS 12; TV 4th Gen, tvOS 12;  Airport Express w/ Airplay 2

From the Apple Gift card page;

Gift Cards - Apple

App Store & iTunes Gift Cards are solely for the purchase of goods and services on the iTunes Store, Apple Books, Apple Music, and the App Store.

Give them an Apple Store Gift Card and they can get Apple hardware and accessories at any Apple Store, at Apple.com, or by calling 1‑800‑MY‑APPLE.

Two completely different gift cards made for two completely different and specific uses. Don't want to believe me, test it, go online to apple.com and try to buy hardware by redeeming an App Store gift card.