The first time a user generates an XRP ledger address for a XRP wallet, that address does not become immediately ‘active’. If the destination address is not ‘active’, a minimum of 10 XRP must be sent to pay the account reserve and activate the address, this one-time fee (activation fee) is required by the XRP ledger network and is non-refundable.
If you are trying to add funds from an external XRP wallet to one of your Uphold cards, via XRP ledger network, you need to generate an XRP ledger address. Once this address is generated, it is already ‘active’, which means, you can send any XRP amount from an external XRP wallet to one of your Uphold cards without including the activation fee.
If you are trying to send funds from one of your Uphold cards to an external XRP wallet, via XRP ledger network, you might need to include the activation fee amount, depending on the state of the destination XRP address. Please read article How do I send XRP from my Uphold account to an external XRP ledger address? for more information.