Simple render with python using requests.

import json
import requests

url = '<https://api.mockupsjar.com/mockups/render/rustic-frame>'
headers = {
    "Authorization": "Bearer API_TOKEN"
}
data = {
    "zoomLevel":1,
    "format":"jpg",
     "input":[ "<https://dummyimage.com/400x600/4697c2/fff.jpg>"]}

r = requests.post(url, headers=headers, json=data)
print(r)
print(r.json())

Output

<Response [200]>
{'status': 'success', 'data': {'slug': 'rustic-frame', 'name': 'Rustic Frame', 'status': 'successful', 'zoomLevel': 1, 'format': 'jpg', 'result': {'url': '<https://mockupsjar-production.s3-eu-west-1.amazonaws.com/renders/mockup-IKqB4B8GQFx2C2iz.jpg>', 'previewUrl': '<https://mockupsjar-production.s3-eu-west-1.amazonaws.com/renders/HYgfLzeFJ30WtFTv-6RwXQHYLWezJyCax.jpg>'}}}

Output image