Hi @praneshJ :
'Web roles' doesn't seem to be a standard entity(There is no'Web roles' entity in my CDS database), do you give me a screenshot like this?

In addition,if you want to establish a mapping between records between two interrelated entities:
Firstly, mapping between related entities does not use primary keys or foreign keys.
In the case of a One-to-many relationships, the Look up field will be created on the related entity Instead of using primary keys or foreign keys.
The value stored in Lookup field is the ID of the associated record
Secondly, there are many ways to establish a mapping between records between two interrelated entities:
I will introduce you to the two most common methods:
Method1:Using Relate function.(Canvas App)
I think this link will help you a lot:
Relate and Unrelate functions in Power Apps
Method2:Using Edit record function.
the relationship between Account and Contact is 1:N
Step1:Data-Entities-your main entity-data-Edit record

Step2:Related-related entity

Step3:Add New XX or Add Existing XX
*Contact is my related entity

Best Regards,
Bof