This is a guide explaining how to get logs on various launchers. If there is a launcher you want to see added reply in the comments.
Once you have logs you can either upload them as an attachment if they are in the form of a file, or if its in clipboard format you can put on a paste website.
Vanilla Launcher (Official one provided by Mojang)
Minecraft Server
MinecraftForge Installer
ModLists
Note: We are not officially affiliated with any of the 3rd party launchers, we cannot fix their errors and cannot attest for differences or problems in them and are going from personal experience.
CurseForge Launcher
TLauncher
MultiMC (and derivatives)
GDLauncher
Coming soon: ATLauncher