Thank you for sharing. It's very helpful 🙂
The link includes a PHP Library, very useful for PHP developers. But, for REST API, I was able to get the REST API to work by looking at some other links through the above link.
Here's what worked for me to create a subscriber -
URL
https://www.authoremail.com/email/api/lists/**{{your-list-id}}**/subscribers
Request Type
POST
Header
Key: X-API-KEY
Value: {{your-api-key}}
Request Body
Type: Form Data
EMAIL: {{email}}
FNAME: {{first_name}}
LNAME: {{last_name}}

