If you are running into an error in regards to seeing an insufficient ETH error when trying to send either ETH or an ERC-20 Token, you've come to right place!
In order to send any ETH based tokens such as USDT, DAI, USDC etc. you need to have some ETH to cover the fee. These are considered ERC-20 tokens and are a part of the ETH network and require ETH or you will not be able to send or trade it anywhere. Edge makes 0 profit from those fees and instead goes to the ETH network to process your transaction.
If you are not sure, a list of ETH tokens can be seen here: https://etherscan.io/tokens
Transaction fees for sending ETH or ERC-20 tokens vary greatly and can be as low as $1 and even $100 or higher depending on the traffic on the network and complexity of the transaction. You can take a look at what the average fees are here: https://www.gasnow.org/
We recommend purchasing about $20-$50 of ETH as that should be enough to cover most basic transactions during normal traffic and also gives you enough to do a few transactions. However these recommended amounts can change drastically depending on the congestion on the network as noted earlier.
Remember, that if you are trying to send an ERC-20 token you will be required to have some ETH in order to covert the fee to get the transaction processed. Without any ETH you cannot send the funds out at all.
Let me know if you have any questions.