Once an expense claim has been submitted, the approvers associated with it cannot be changed. The options below can help resolve this.
Set a user to approve on behalf of the leaver. You may also need to change the approval route to add or remove the relevant members.
Ask the user to unsubmit the claim, amend the approval route to add and remove the relevant members, and then resubmit.
Request that an administrator temporarily reactivates the leaver's Access Evo account to allow access via a password change. Once the claims have been approved, the account can be deactivated.
This is not recommended unless the email address is on the company domain, so the password change can be handled by the IT department.
Once the claim can be viewed for approval, you can process it in the usual way.