[discord.js] Adding reactions

I need help on how to make my bot add reactions after it has sent a message. Example I send !hello it answers with hello and then an emoji with the reactions.

You can get tons of assistance on the discord.js Discord server. Someone might know here but that server is filled with people who actively use (and develop) the library. I also find their documentation to be quite good. And there are many video tutorials which provide you a way to learn at your own pace.

This guide may help you.