My friend has been working on a different website which transfers payments to Upwork. The problem is his Upwork profile is not approved yet. So can he still receive payments into his profile and then withdraw it?
If the company is on Upwork, they can bring a freelancer onto the platform to complete projects for them through Upwork. Unless the freelancer has an account that is approved for the general marketplace on Upwork, they would be working only with that company. You can find additional information about this here.