How to encrypt a file with public key and decrypt with private key and passphrase

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encryption

.NET4.5

C#6.0

Hi,
I am trying to encrypt a file using a public key (e.g. abc_public.asc) generated through PGPTool, which was shared with the client. The client shared a private key (xyz.asc) in return, in which the PGPTool shows as 'Public' (xyz.asc) and 'Key Pair' (abc_public.asc).

I am able to encrypt the file successfully, however when trying to decrypt it throws "Org.BouncyCastle.Bcpg.OpenPgp.PgpException: 'Org.BouncyCastle.Bcpg.OpenPgp.PgpPublicKeyRing found where PgpSecretKeyRing expected'"

The encrypted file when trying to decrypt with the PGPTool, it works but not through the code. Please help where am I going wrong.

What I have tried:

PGPEncryptDecrypt.EncryptFile(@"C:\test\test.txt", @"C:\test\test.txt.pgp",
         @"C:\test\abc_public.asc", false, true);


   PGPEncryptDecrypt.Decrypt(@"C:\test\test.txt.pgp", @"C:\test\xyz.asc", "hello@2022",
       @"C:\test\test_app.txt");