What is ERC20

Anyone can use smart contracts if they have Ethereum’s native token ether , which can be bought on cryptocurrency exchanges.

To withdraw a token balance, you need to execute the transfer() function on the token contract . So in order to withdraw all tokens, you need to execute the transfer() function on all token contracts. You can create a function that withdraws any ERC-20 token based on the token contract address that you pass as an input.