Seems to be documented, surprisingly: https://<INSTANCE>.service-now.com/cancel_my_transaction.do

https://support.servicenow.com/kb?id=kb_article_view&sysparm...

Or you can type “cancel_my_transaction.do” in the navigator filter bar. Related tip: you can quickly bring up any table by typing “table_name.list” (s/.do/.list/ from the single-item url) there instead of poking around for a link. “sys_user.list” is probably the one I use most often.