first login to your gmail account and under My account > Sign In And Security > Sign In to google, enable two step verification, then you can generate app password, and you can use that app password in .env file.
Your .env file will then look something like this
MAIL_DRIVER=smtp
MAIL_HOST=smtp.gmail.com
MAIL_PORT=587
MAIL_USERNAME=myemail@gmail.com
MAIL_PASSWORD=apppassword
MAIL_ENCRYPTION=tls
Don’t forget to run php artisan config:cache after you make changes in your .env file.