Depending on your sales flow, you may opt to set your sales/commissions on pending approval. To do this, follow the steps below. 

Step 1: From the Admin Dashboard, click Referral Programs

Step 2.Click the pencil icon below actions for that program.

Step 3. Click show advance settings and make sure that All sales from this referral program must be approved before being added is  check click continue.

Step 4. To check once commission approved from your admin dashboard click the email under  Recent sales and leads.

Step 5. Check the commission amount and status should be approved then submit.

Step 6. To check the commission added to the invoices. Go  rewards.

Step 7. Manage invoices. All of the approved sales will be added to an open invoice.