MailerLite
You can use MailerLite for your email setup. SaasAble already has a working example on the "coming soon" page, which you can also utilize. You need to provide your key values in the .env file.
Setup:
Mailer lite account setup
Please create Mailer lite account: https://accounts.mailerlite.com/
Integrate API: https://dashboard.mailerlite.com/integrations/api
You need to get all three things from here
API Token
API URL
Group ID

Set the values from your Mailer lite account to .env file:
We have already set API to send mail in the coming soon page: