import requests

url = "https://{FUSION HOST}/api/connectors/plugins"

headers = {"Content-Type": "application/zip"}

response = requests.put(url, headers=headers)

print(response.json())

{
  "pluginId": "lucidworks.slack",
  "status": {
    "action": "INSTALL",
    "status": "SUCCESS",
    "message": "Plugin lucidworks.slack was installed successfully."
  }
}