Error on Capture Order: "Authorization failed due to insufficient permissions"

[Nditah]

I am building a fullstack application integrating Paypal.
I followed the paypal example here and the version for client frontend works.

However, the fullstack version works during creating orders but fails during capturing orders.

mode: sandbox
node: 16

{
  name: 'NOT_AUTHORIZED',
  details: [
    {
      issue: 'PERMISSION_DENIED',
      description: 'You do not have permission to access or perform operations on this resource.'
    }
  ],
  message: 'Authorization failed due to insufficient permissions.',
  debug_id: '52a2ebfb6540',
  links: [
    {
      href: 'https://developer.paypal.com/docs/api/orders/v2/#error-PERMISSION_DENIED',
      rel: 'information_link'
    }
  ]
}