Picsart's Creative APIs at https://api.picsart.io/tools/1.0 edit images: remove backgrounds, upscale, enhance, apply effects. Point them at an image with image_url. This is a multipart form — in PostTaco, the Body tab's Form mode.
Get a key in the Picsart console and send it as the X-Picsart-API-Key header. In the examples it's written {{PICSART_API_KEY}}.
Full reference: https://docs.picsart.io/
Example image from Picsart's docs.
curl -X POST https://api.picsart.io/tools/1.0/removebg \
-H "X-Picsart-API-Key: {{PICSART_API_KEY}}" \
-F image_url=https://cdn140.picsart.com/13902645939997000779.jpg
curl https://api.picsart.io/tools/1.0/balance \
-H "X-Picsart-API-Key: {{PICSART_API_KEY}}"