How to manage Plesk via REST API?

To list all domains:

# curl -k -X GET -u admin:password -H "Content-Type: application/json" -H "Accept: application/json" "https://203.0.113.2:8443/api/v2/domains"
[
{
"id": 1,
"created": "2018-12-17",
"name": "example.com,
"ascii_name": "example.com",
"guid": "4e0da092-de42-4048-9459-989b5cb942f2",
"hosting_type": "virtual"
},
{
"id": 2,
"created": "2018-12-17",
"name": "example.org",
"ascii_name": "example.org",
"guid": "f1b6e826-c884-4fa2-832b-5813c09002d3",
"hosting_type": "virtual"
},
{
"id": 3,
"created": "2018-12-17",
"name": "example.net",
"ascii_name": "example.net",
"guid": "03f62600-db70-4a94-9818-ab12a57a1425",
"hosting_type": "virtual"
}

To create a mailbox:

# curl -k -X POST -u admin:password "https://203.0.113.2:8443/api/v2/cli/mail/call" -H "accept: application/json" -H "Content-Type: application/json" -d "{ \"params\": [ \"--create\", \"jdoe@example.com\",\"-mailbox\", \"true\", \"-passwd\", \"1qazXSW@\" ]}"
{
"code": 0,
"stdout": "SUCCESS: Creation of mailname 'jdoe@example.com' complete",
"stderr": ""

Show the information about the subscription:

# curl -k -X POST -u admin:password "https://203.0.113.2:8443/api/v2/cli/subscription/call" -H "accept: application/json" -H "Content-Type: application/json" -d "{\ "params\": [\"--info\", \"example.com\"]}"

Show help for mail utility:

# curl -k -X POST -u admin:password "https://203.0.113.2:8443/api/v2/cli/mail/call" -H "accept: application/json" -H "Content-Type: application/json" -d "{ \"params\": [ \"--help\" ]}"

Use CLI gate to check SpamAssassin status for the mailbox:

# curl -k -X POST -u admin:password "https://203.0.113.2:8443/api/v2/cli/spamassassin/call" -H "accept: application/json" -H "Content-Type: application/json" -d "{ \"params\": [ \"--info\", \"jdoe@example.com\" ]}"

Use CLI gate to add additional user using secret key instead of admin password

# curl -k -X 'GET' -H 'X-Api-Key: ******************' 'https://203.0.133.2:8443/api/v2/cli/user/call' -H "accept: application/json" -H "Content-Type: application/json" -d @user.json

The content of the user.json file:

CONFIG_TEXT: { "params": [ "--create", "adduser", "-owner", "admin", "-passwd", "samplepassword", "-cname", "User", "-role", "webmaster" ] }