Does interview scheduling through O365 require both the interviewer and the scheduler to have O365?

Summary:

My client is rolling out interview scheduling through O365 and we are not clear who exactly needs O365 for the solution to work. The documentation does not say this explicitly. It mentions that it does not work with on-prem, but does that apply to interviewers who do not have O365? We also have recruitment booster.

Content (please ensure you mask any confidential information):

I need clarity on the who specifically needs access to O365 for this solution to work.

Version (include the version you are using, if applicable):

24C

Code Snippet (add any code snippets that support your topic, if applicable):