If there is not already a way - unknown to me - to unbind all keybindings for a game, with one keypress, then please make a button on the top of the first keybinding. That should read [Unbind ALL]. Next to this button should be another, saying [Reset ALL Keybindings]
Welcome to the community! 
If you’re looking for a way to disable (and re-enable) hotkeys, yes that feature exists. It’s found under the Customisation tab in the desktop software’s settings, for Pro members.
But if you’re looking for a way to clear all the default hotkeys, for example to replace them all with your own, no, that’s not a feature at this moment in time. They currently need to be removed manually one at a time (delete key) and reset again one at a time (backspace). Might save a bit of time for trainers with a lot of cheats if it was possible to clear the defaults in one press.