Login to your account that is associated with your hotspots via Helium World. Once you are viewing your dashboard, head to your account management and select Manage Wallet
You will be redirected to a new tab on Privy with your associated wallet, from here you can click on Add Funds
You will be presented with four separate options to choose from: Pay with card, Transfer from an exchange, Transfer from wallet or Receive funds
Choose the method of transfer that best fits your needs, and follow the on screen instructions to complete you deposit.