Error while creating a test page using graph API explorer

I'm trying to read Facebook comments on my Page feed via Webhooks. I installed the app to my page and configured the Webhooks properly. That did not work. Since our app is still in Development mode (without approval from Facebook), I thought trying with a Test user account would help my cause.

Then, I tried creating a test user account to see if that helps. To proceed further, I'm trying to create a test page for checking the Webhook. But I'm stuck in that step with the following error:

`
{
"error": {
"message": "(#100) Could not create page because cover photo could not be added, make sure it is of valid size",
"type": "OAuthException",
"code": 100,
"fbtrace_id": "A6F04ktwiJKthmniHwOAFUi"
}
}
`

Request URL - test-user-id/accounts

This is the JSON body i sent with this request .
`{
"picture": "https://images.pexels.com/photos/771742/pexels-photo-771742.jpeg?auto=compress&cs=tinysrgb&dpr=1&w=500",
"cover_photo": {
"url": "https://res.cloudinary.com/ds3lm5yfx/image/upload/v1594841149/19756550_800026650156784_1191270699014302061_n.jpg_qgnrpn.jpg"
},
"name": "Test page",
"category_enum": "MEDIA",
"about": "A"
}`

@zpao @passy @killian @ChrisChinchilla @jamesgpearce

Any help would be appreciated