NOT_AUTHORIZED when trying to create a Product using POST /v1/catalogs/products

[Peer2]

{"name":"NOT_AUTHORIZED","message":"Authorization failed due to insufficient permissions.","debug_id":"5969431cc6fb5","details":[{"issue":"PERMISSION_DENIED","description":"You do not have permission to access or perform operations on this resource."}]

What kind of permission is needed and how do i get it?

POST https://api.sandbox.paypal.com/v1/catalogs/products

returned  403 Forbidden

Thanks in advance for any advice or pointers...