Conga Contracts for Salesforce is migrating its backend application on May 2nd, 2020. IP addresses will change as a result of this. If your org whitelists the current IP addresses, you will need to update before May 2nd in order to keep using the backend functionality of the application. If you are not whitelisting these IPs, then no changes are necessary.
The following is a list of current IP address and what the new IP address will be as of May 2nd:
Asia Pacific IP Address Changes
EU IP Address Changes
NA IP Address Changes
These IP addresses are subject to change.