Hostinger's API at https://developers.hostinger.com/api manages VPS, domains, DNS, and billing.
Get a key at hPanel → Account → API. Send it as Authorization: Bearer <key>. In the examples it's written {{HOSTINGER_API_TOKEN}}.
Full reference: https://developers.hostinger.com/
curl https://developers.hostinger.com/api/vps/v1/virtual-machines \
-H "Authorization: Bearer {{HOSTINGER_API_TOKEN}}"
curl https://developers.hostinger.com/api/domains/v1/portfolio \
-H "Authorization: Bearer {{HOSTINGER_API_TOKEN}}"