Cutout.pro's API at https://www.cutout.pro/api/v1 removes backgrounds and edits photos. mattingByUrl takes an image URL and returns the result as base64 in JSON. Errors come back as HTTP 200 with a nonzero code.
Get a key from your Cutout.pro account and send it as the APIKEY header. In the examples it's written {{CUTOUT_API_KEY}}.
Full reference: https://www.cutout.pro/api-document/bg-remover
mattingType: 6 general, 1 or 3 portrait, 2 object.
curl "https://www.cutout.pro/api/v1/mattingByUrl?mattingType=6&url=https%3A%2F%2Fwww.remove.bg%2Fexample.jpg" \
-H "APIKEY: {{CUTOUT_API_KEY}}"