Express Checkout NVP SOAP Is it deprecated

[NM1991]

We are trying to integrate our Application with Paypal. The main aim is to create the Billing Agreements and Authorizing /Capturing the Order Payments against the Billing Agreements.

I can establish this functionality using PayPalMerchant-net451. But this is being mentioned as deprecated. I saw PayPalCheckoutSdk for the latest version but my app does not support this one as it is dependent on the '.Net Standard' and my app is based on .Net Framework . So can anyone please help me to figure out is it ok to use PayPalMerchant-net451 to integrate with Paypal.