Can't purchase v-bucks

Consumables like Fortnite V-Bucks have to be purchased by the account that is supposed to use them.

Unfortunately, there is no way to transfer consumables to a different account. While it is possible to buy a game and some DLCs that your son can play thanks to the Home Console setting that shares your game purchases with the first console you set up with
your account, consumables can't be shared to a console.

Therefore your son can't see the V-Bucks in his account, as the V-Bucks are stored on your account, and not shared to the console.

In order to get your son V-Bucks, you would have to buy him a currency gift card, that your son then redeems, and with which he can then buy V-Bucks for himself.

Hey,

Fortnite uses it's own virtual currency named V-Bucks.

You should be able to purchase V-Bucks with your Xbox currency and with those V-Bucks purchase in-game items on Fortnite.

Hello Duffy how are you?

My name is Ezequiel I'm an Independent Consultant.

If you purchased V-Bucks through the Microsoft Store or PlayStation®Store, log into Fortnite on the corresponding platform to update your balance before accessing other Shared Wallet supported platforms.

WHY ARE THE V-BUCKS I PURCHASED NOT SHARED ON ALL PLATFORMS?
Currently, only PlayStation, Xbox, PC, Android and Cloud Gaming services support the Fortnite Share Wallet. This means that your V-Bucks balance may change depending on which platform you are on. Examples:

Example 1: 1,000 V-Bucks purchased by PC.

On PlayStation, Xbox, PC, Android and Cloud Gaming services, your balance will be 1,000 V-Bucks.

On Nintendo Switch, your balance will be 0 V-Buck.

Example 2: 1,000 V-Bucks purchased via Nintendo Switch.

On PlayStation, Xbox, PC, Android and Cloud Gaming services, your balance will be 0 V-Buck.

On Nintendo Switch, your balance will be 1,000 V-Bucks.

Example 3: 1,000 V-Bucks purchased by PlayStation. 500 V-Bucks earned by unlocking Battle Pass tiers on any platform.

On PlayStation, Xbox, PC, Android and Cloud Gaming services, your balance will be 1,500 V-Bucks.

On Nintendo Switch, your balance will be 500 V-Bucks.

The restrictions described above only apply to the purchase of V-Bucks. All in-game content purchased with V-Bucks (eg Outfits) is available on all platforms.

https://www.fortnite.com/news/v-buc...ite-shared-wallet?sessionInvalidated=true#FAQ

This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.

As everyone is saying you can't gift them.

You have to go in the shop in order to purchase V-Bucks.

Hope this helps

V-Bucks you purchase from the Microsoft Store can be used on Xbox, PC or mobile, but can't be transferred to or used on other consoles.