On Start TTP Session , PerpareFailed

[Zakariya5567]

I am running the Sample Test App. The create session was done got the token, App account is verified now.
But getting this error when clicking on "Start TTP Preparation"
Error: Prepare Failed. Error That indicates preparation Failed.

public func initializeSession() async throws {
    do {
        await MainActor.run { self.isBusy = true }
        try await self.fiservTTPCardReader.initializeSession()
        await MainActor.run {
            self.isBusy = false
            self.cardReaderActive = true
            self.readyForPayments = true
        }
    } catch {
        await MainActor.run { self.isBusy = false }
        throw error
    }
}