When will I get pro account for 3 month after I invite friends?

What link do I need to send to invite friend to sketchfab and get pro account for three month. Do I just need to send sketchfab.com to my friend or others link? How can Sketchfab know who I invited?

I found a link in the internet https://skfb.ly/Cr7H and I have sent to 5 people. Will I get pro account?

We’ve discontinued the friend referral program for the time being. We may bring it back in one form or another in the future.