I believe you will find the Concur invoices in the Help upper right corner of your Concur page. Once on the Concur Support page look for the menu Billing.
Or contact your Concur rep for assistance.
Hope this helps.
Thank you for your reply,
Can you please confirm with the screenshot below if it's a role level issue?
I find the invoices on the Concur support page > Billing.
I am not sure is a role. check with your concur service rep if they need to set up something for your access.