This guide will tell you how to fix the server did not join Error in The Hello launcher.
These errors occur if you join a premium server with a cracked account. You can join only cracked servers with a cracked account. You can search it on any browser Minecraft java cracked servers and find many of them.
You will get the same error with the Aternos server. To solve this error for Aternos, you have to go to its official website and log in to your account on the website which has your server. After that, click on the three lines in the top left corner of the screen and tap on Options. Scroll down and checkmark the cracked option. Now you can play this server using your premium or your cracked account.