OAuth error when setting up Connect Adobe Sign- SharePoint Online

Hi there,
I'm a newbie here and its been diffcult trying to integrate Adobe sign into our SharePoint Online 
I have installed the Adobe Sign app in sharepoint online and when click the icon app it redirects me to the below

and then when i click on the "Establich Sharepoint Connecton Connect " i use my adobe login with username and password.

Thats when i get the error

OAuth error failed

I do have this plan  and i also created a  trial enterprise plan and both her displaying the same error

Can you please let me know what i'm doing wrong

Thanks in Advance