Freelancer invoicing option allows your listed freelancers to submit invoices to your team for approval. By default this option is disabled but you can easily turn it on in the Admin tab. Scroll down to the Finance section and check the box on 'Freelancer invoicing'.
Freelancer invoicing is enabled, your freelancers will be able to submit more than one invoice for their completed Tasks (for example, expenses).
See this article on how freelancers can Upload an Invoice here.
Any questions? Please reach out to firstname.lastname@example.org!