To withdraw ALTS (short for "alternative coins," a term used to refer to cryptocurrencies other than Bitcoin), you will need to follow these steps:
Find a cryptocurrency exchange that supports the ALTS you want to withdraw. Not all exchanges support all cryptocurrencies, so you will need to find one that specifically supports the ALTS you are interested in.
Create an account on the exchange and complete any necessary verification processes.
Transfer your ALTS from your wallet to the exchange. This can usually be done by entering the address of the exchange as the recipient of the transfer.
Once your ALTS are in your account on the exchange, you can place a sell order to convert them to the desired fiat currency or another cryptocurrency.
After the sell order has been completed, you can withdraw the funds to your bank account or another destination of your choice.
Keep in mind that each exchange has its own specific process for withdrawing funds, so you may need to follow slightly different steps depending on the exchange you are using. Be sure to read the exchange's documentation carefully to ensure that you are following the correct procedure.