Since we don't use any web servers to store your API keys, we can't manage your API keys for you. API keys on one machine don't sync with HyperTerminal on another machine even if you log in using the same credential. It needs to be added/ edited/ deleted on each of these machines individually. Only HyperTerminal or a PC/ Mac owner/ administrator can manage these API keys.
You can delete an API key for an exchange by going to Key Manager in HyperTerminal. Go to right-hand side toolbar and click on the key icon. It brings you the API key management panel. Select the exchange you want to edit/ delete the key. There are two action buttons - Edit & Delete. Key Manager works similarly on both Windows and macOS.
For whatever reason you don't have access to HyperTerminal, you can delete the keys by following methods.
Go to start menu search and type Credential Manager. Once you are in the Credential Manager, select Windows Credentials. Under Generic Credentials, you can see HyperLinq accounts. This account entry is what holds your API keys. You can select the one you want to edit/ delete, you get the Edit & Remove options.
Press Cmd+Space and type Keychain. Once you are in the Keychain, select Passwords in the Category section. Search for HyperLinq. You should see an entry which you can double click to open the manage window.
Details for Linux coming soon.