Agreement and Signing URL expiration date

Hello, I am using AdobeSign Rest API V6, my question is when creating an agreement, if no expiration date is specified, will the created agreement have a default expiration date or it will never expire?

Also, when requesting the signing url for the agreement, the url returned by Adobe will have an expiration or as long as the agreement is not expired and not signed, then the signing url will remain active and valid?