TypeError: Argument 1 passed to guessMimeType() must be string not object

Is $response a string? It is supposed to be one.

Hi @cilefen

No, It's an object retrieving from another source. like the below.

{
"openapi": "3.0.2",
"info": {
"title": "Open lorem",
"description": "simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s,.\n\n# Authentication\n\n

",
"version": "1.0.0"
},.....
.....
....

You must pass a string which contains the file contents. See https://api.drupal.org/api/drupal/core%21modules%21file%21src%21FileRepo...