if you do not have a sendgrid account, signup fro a free one here
in sendgrid web ui, go to account --> api keys
click on create API Key
select restricted and enable mail send.
once api key is created, copy the key to your env file
the key is only show once !!!
SMTP_ADDRESS="smtp.sendgrid.net"
SMTP_IDENTITY="apikey"
SMTP_PASSWORD="your api key"
SMTP_FROM="your from address"
SMTP_PORT="587"
SMTP_STARTTLS="true"