Anyone knows where I can get a Diploma certificate in Assamese by paying.

I am applying for a job and the requirement is that I have to have class 10/12 or any certificate showing I studied assamese. Unfortunately, I studied assamese till class 8 so I don't have any such certificate. Now, I don't have time to join a diploma course and get the certificate legally. So, If anyone knows where I can get diploma certificate in Assamese by paying it would be really helpful.