Thanks to everyone for the answers and saved me from sending the depot to a service that does not deserve it. 0.0000004 BTC is unsendable sum. These are some kind of ridiculous trolls not a service. (Very respectable top site among crypto entusiasts. And these trolls own a top crypto site and don't even know that it's technically impossible to send such dust which speaks about the extreme incompetence of these schoolboys)
Some of these services know what they're doing, it's either they want to use that dust transaction for their own selfish interests and need someone to do it for them. However, why did you wanted to use their service when you can send bitcoin out from your own self custody wallet by yourself.
Dust transaction can be sent by scammers into your wallet and use it to compromise your wallet if you don't freeze it. Be careful with the services you are using online and verify before using them. You can't send such an amount.