How to connect an external wallet?

During the sign up process, an internal wallet is automatically created for the user. This process reduces the requirement of having to install any external wallets to play the game, while also reducing the risk as the in-game items are then directly sent to the internal wallet and are safe in case the external wallet is hacked.

But, users can add upto one external wallets to their account. This wallet can be used for showcasing ownership of Apartment NFTs and external integrated Skins.

How to connect to an external wallet?