dynamic RelayState variables in IDP initiated SSO

Hello Experts,

I have a requirement, where we need to setup a SAML SSO with SP as IDP initiated.

But I need to pass Relay state Dynamically with the assertion.

for example :

SP entity ID : https://spentity.abcd.com

ACS: https://spentity.abcd.com/smalv2acslocation

relay state : for portal 1 : https://spentity.abcd.com/saml/realy?12345

for portal 2 : https://spentity.abcd.com/saml/realy?1234567

how can I do this ?

I am using ver 13.1.0.1 , is there a option to map dynamic RelayState variables ?

thanks in advance.