TLauncher has problems connecting to Aternos servers because it removes essential features from Minecraft.
Our recommended solution: Don't use TLauncher. When using TLauncher you probably get a connection timeout error, it might look like this:
io.netty.channel.AbstractChannel$AnnotatedConnectException:
Connection timed out: no further information:
If you Really Want to use TLauncher, Ask our Admins to Provide our Dynamic IP to play on you account
or just like this: kingsduck3.aternos.me:22860