CTS — Not able to login to the CTS portal

I am not able to login to one cognizant portal.

Getting below error message
AADSTS90072: User account 'nandish.[protected]@GMAIL.COM' from identity provider 'live.com' does not exist in tenant 'Cognizant' and cannot access the application 'https://onecognizantexternal.cognizant.com'(ENT_onecognizantexternal_...⇄ in that tenant. The account needs to be added as an external user in the tenant first. Sign out and sign in again with a different Azure Active Directory user account

Earlier I logged into the portal and completed BGV and pre-joining formalities.

Please help me out to resolve this issue