This is perfect solution man. The submit button was highlighted green before i even completed typing the otp.
Btw, since i logged in into incognito mode, cookies and all were not needed to be cleared since incognito does not access them.
Thanks for your help really. I had only one chance left to request otp when i came accross this page.
@fiverr_admin - this topic was opened in 2018 and this issue still persists. Maybe try fixing it atleast in this decade. This affects all services which require submit code button.