I successfully referred GUVI to three of my friend and received coupon code of 100% of on any course but when I completed IITM Python Hindi course and while getting certificate there was no option to enter any code and it kept me asking approx 2,000 INR for certificate.
Please GUVI help me to get the free certificate, it was so hard get those 3 refer and in hope of getting certificate I completed whole course with so dedication.
I also talked to Vinish Vivek Sir (creator of this course) about my issue and he helped me alot with other issues but for certificate he suggested me to contact GUVI team.