Deactivate Buyer User
Deactivate a buyer user
        PUT
    /buyers/{buyerId}/buyer_users/{buyerUserId}/deactivate
  
  curl \
 --request PUT 'https://stg.getfoundation.com/api/external/v1/buyers/{buyerId}/buyer_users/{buyerUserId}/deactivate' \
 --header "X-API-Key: $API_KEY"