in a second terminal window:
in a third terminal window:
If you don't have a proxy created you can simply do it by a click of a button in a secured manne!.
Once created you can fund your proxy with Mock DAI and of course eth and any erc20 asset in a mainstream scenario.
function execute(address _target, bytes memory _data)in your proxy as the owner and pass the external contract's address as the _target address your transaction will fail if you do that since when you interact with any external contract via proxy the storage context will always be that of the proxy contract.