Template for importing data from Axosoft OnTime to YouTrack?

Hello everyone, We are in the process of migrating from Axosoft OnTime to YouTrack and I need to use YouTrack's csv python importer to import all our data from OnTime to YouTrack. Just wondering if anyone has done that before. If you did, any chance you can share the mapping file you created? Any pitfalls to watch out for ?

Thanks in advance!