Hello,
To deposit to the hot wallet, simply use any address generated from that wallet that is NOT assigned to a user.
One way to ensure that you get an address that is not already a user deposit address, go to Wallets → Cold Storage in your admin screens. Choose your coin and hit the deposit button.
If you want to know more about the cold storage section, you can visit the Cold Storage chapter in the documentation. It’s just an easy way to deposit/withdraw to and from the hot wallet without affecting user balances. The view also lets you see what the sum of user balances is, so that you know what percentage of the balances is covered by the funds you have online.
Please let me know if you have any other questions.
with regards
P.S. I have moved your question to the general discussion because the answer is not specific to CoinPayments.