Which connector?:

Xero

Additional details:

Apps created in Xero after March 4th are issued a new set of scopes that are more granular than before. The old scopes are still supported, but will be deprecated next year. 

Xero introduced a usage-based commercial model based on data egress. Some scopes have additional security requirements and costs involved such as accounting.journals.read which now is only available to Xero partners on the Advanced tier which costs $895USD/month.

Additionally, while the custom connection app allows for granular scopes, it is only available to customers in Australia, New Zealand, the UK, and the US. We are a Xero partner located in Canada; therefore, this is not an option for us so we need to use the Web App configuration.