install dependencies

npm install 

make a .env file to login gmail account

USEREMAIL=""
PASSWORD=""

fill in peserta.csv, (feel free to add more columns depending on the template, however email column is used for the destination email)

fill in template/body.txt and template/subject.txt
instances of a column name surrounded by # will be replaced by the columns value

run the program

node send_gmail.js

if any error occurs during login, you can refresh or page back to login manually and the program will continue once you have logged in