hello I sent some agoras to omniwallet and now I want to test to send some out there. but I cant becouse this error:

Your 'From Address' does not have enough BTC to complete this transaction. Please select a different address or send enough BTC to cover the Total transaction cost.

Must I have BTC in order to cashout my agoras ? is this normal ? first time I see I need btc to send some alts... This confuses me.