How can I enable pages_manage_metadata permission when setting up meta lead ads webhook

[Kamal-Moha]

I'm trying to retrieve lead info when a user fills out a lead ad. I'm following the docs here https://developers.facebook.com/docs/graph-api/webhooks/getting-started/webhooks-for-leadgen/

Though when I try to have the page install the Webhooks configured-app, I get the below error;
{"error":{"message":"(#200) Requires pages_manage_metadata permission to manage the object","type":"OAuthException","code":200,"fbtrace_id":"AnThii7m2-S6WN_UH4Y-Jz"}}

When I'm creating the page access token using this link https://developers.facebook.com/tools/explorer, I don't see the permission pages_manage_metadata and I can't add it.

These are the permissions I see and the pages_manage_metadata permission is not included

I'm still in development and want to make sure everything works as expected before I can submit app for review.

I'm the administrator of this page and the app, I don't know why I can't enable this pages_manage_metadata permission. Please help