如何通过merchantIdInPayPal或merchantId获取paypal用户的用户信息

I want email id PayPal user through PayPal merchant ID

I am applying the chained payment system ( Adaptive Payments ). In this process, I need email id of the sellers/receivers.

I have successfully completed the setup of upfront onboarding and getting below response in REQUEST

Array ( 
    [mode] => isu 
    [merchantId] => DEMOPAYPAL 
    [merchantIdInPayPal] => *********** 
    [permissionsGranted] => true 
    [consentStatus] => true 
    [productIntentId] => addipmt 
    [isEmailConfirmed] => true 
    [accountStatus] => BUSINESS_ACCOUNT 
)

There is no email id in response and PayPal Document saying that merchantIdInPayPal is the payer id and I don't know how to do payment by merchant ID

For Adaptive payment, I have used below document

https://www.formget.com/paypal-adaptive-payments/

Then, I tried to get user email by the merchant ID.

Please help me with this complex process.

Thanks in advance