The HTTP 403 Forbidden response status code indicates that the server understands the request but refuses to authorize it.
My guess here is that the account you authenticate with Xero doesn’t have permission to access the resource you are accessing.
Example, let’s say you want to create an invoice, but the authenticated user doesn’t have permissions to write permissions on invoices, so you get 403 when you try the create the invoice with this user.
Now, I think Xero is using OAuth 2.0 authentication flow. This means in this case that the use isn’t granted the scope related to the action over the resource you are accessing. Pipedream builds and manages OAuth apps, so in this csae my advice would be is that you identify the resource you are trying to access, and which action you want to do against it (read, write, create, update), then look for the Xero app at the App store to see the scopes listed and cross check with Xero docs to confirm if it is missing from the OAuth 2.0. If/when actually missing report to Pipedream so that they add the missing scope to your app. If the scope is already in place with the Pipedream Oauth app then you need a user with higher permissions i.e. with the right scopes.