How do I map a valid project key when importing data from Axosoft?

[Christina Gheorghe]

I'm working on importing data from Axosoft to Jira. I have created a .csv file and I am at the point where I map the CSV fields to Jira fields. Jira will not let me move on until I have mapped a field to project key and one to project type. Jira seems to want very specific formatting for these fields and none of our prior fields match. Axosoft has a project ID field but not in the right format. I have tried mapping it to an empty field but Jira doesn't want null content. I also tried checking off the
"Map field value column" so I could edit the existing content but that didn't work either.