User's Haveno cryptocurrency account must be used for both sending and receiving or it can be only for receiving?

My BTC wallet (Electrum) generates addresses which I can use for receiving new coins. So I have copied one unused address and set is as my Haveno account.

Now I want to sell BTC on Haveno (I have BTC on different address than the one I have set), so during trade I can send from any wallet or I must send from the one I have defined as my Haveno BTC wallet?

Maybe my question is nonsense, since I do not understand Bitcoin technicals. Thank you