How to trigger Target lambda(Lambda2) based on Source Lambda(Lambda1) status only if Lambda1 is successful(Cannot modify Lambda1)

Hello.

Even without using EventBridge, it is possible to set up notifications to SNS when Lambda is successful, so how about running subsequent Lambdas via SNS?
https://docs.aws.amazon.com/lambda/latest/dg/invocation-async.html#invocation-async-destinations

Lambda functions support Lambda Destinations, which is used exactly for this use case. You can configure and onFailure target and an onSuccess target. The target can be SQS, SNS, EventBridge or a different Lambda functions.

Note that Lambda Destinations is only available for asynchronous invocations. As you said your function runs on a schedule, I assume it is an async invocation so it should work for you.

1. as mentioned above, leverage lambda estimation
2. use component in middle for asynchronous flow, such as SQS,SNS,Eventbridge 3)For synchronous flow you can useInvoke api from Lambda1 to 2, though this highly couples the fictions. https://docs.aws.amazon.com/lambda/latest/dg/API_Invoke.html