on is not defined

i want to write a script that if i chat "!OptionA" will return: Option A: write option A and if i chat "!OptionB" will return: Option B, write option B I have done this: On('ready', () =>{     On('chat:message', (msg) =>{         if ('api' === msg.type && msg.content.match(/^!OptionA/)){             {sendChat('Option A', `write option A`)}         }              })     On('chat:message', (msg) =>{             if ('api' === msg.type && msg.content.match(/^!OptionB/)){             sendChat('Option B', `write option B`)}         })     }) but the system say me "on is not defined). Where i'm wrong?

Your On is using a capital letter. In coding case matters - this should be lower case on. Also you have some extra curly brackets in your sendChat lines. Try this: on('ready', () => {     on('chat:message', (msg) => {         if ('api' === msg.type && msg.content.match(/^!OptionA/)) {             sendChat('Option A', `write option A`);         }     });     on('chat:message', (msg) => {         if ('api' === msg.type && msg.content.match(/^!OptionB/)) {             sendChat('Option B', `write option B`);         }     }); }); note also the semicolons to mark line endings. They aren't always necessary, but are sometimes, and are handy for layout purposes.