Think Exam allows the facility to sell or earn from the tests (monetize).
The selling feature is only available either with a professional or a business account. You can easily upgrade your account to above two accounts, in order to have the monetization of your created tests.
A test taker will first pay online via credit/debit card or using a dedicated coupon code, to attempt the required Online exam.
Payment gateway options; PayPal, PayU money, CC Avenue, Paytm