To test commission assignment without doing a real payment you will need to manually add a payment.
To add a payment manually, go to ~wmtsystemurl~/admin/members in the members area and click on the billing history icon for the member you want to add commission for.
In the popup click the Add Payment link.
Enter a payment amount and date. For Type and Transaction ID you can enter anything or leave blank as it doesn't affect test results.
To apply the payment visit: ~wmtsystemurl~/admin/applyaffiliatepayments.php
To put the button (~orderbutton1~) on the order page you would paste the code ~orderbutton1~ where you want the button to appear. I'm not sure what you mean by dynamic. If you mean that you want the payment to go directly to the member then you would need a pro system, with the commission tracking plugin, with direct payment turned on, and then you would link to the join page and payment to the member is made AFTER they create an account (a key difference as direct payment works opposite from a normal system).