DigitalOcean's API lives at https://api.digitalocean.com/v2 and manages Droplets, databases, apps, DNS, and more.
Get a personal access token at cloud.digitalocean.com. Send it as Authorization: Bearer <token>. In the examples it's written {{DIGITALOCEAN_TOKEN}}.
Full reference: https://docs.digitalocean.com/reference/api/
Droplet limit, email, status.
curl https://api.digitalocean.com/v2/account \
-H "Authorization: Bearer {{DIGITALOCEAN_TOKEN}}"
curl "https://api.digitalocean.com/v2/droplets?per_page=10" \
-H "Authorization: Bearer {{DIGITALOCEAN_TOKEN}}"
curl https://api.digitalocean.com/v2/regions \
-H "Authorization: Bearer {{DIGITALOCEAN_TOKEN}}"