If you are experiencing issues with your Recurly-Salesforce integration which require an escalation to our Salesforce Specialist, then you will be asked to provide Recurly access to your Salesforce org.
Granting access allows specific users inside of Recurly's Salesforce org to impersonate the merchant company Salesforce users and login to their Salesforce orgs to troubleshoot and resolve their issues.
https://help.salesforce.com/apex/HTViewSolution?id=000003910 will help customers who are not familiar with granting login access.
Note that there are two different setup styles, some people will grant login access by clicking on their name, then personal preferences. Some people will grant login access through the global setup screen. Also, please note that you will be granting access to Recurly Admin, not Salesforce.