That solved that error.

# command-line-arguments
./nostrlogger.go:16:17: undefined: nostr.DerivePublicKey
./nostrlogger.go:18:19: undefined: nostr.EncodePrivateKey
./nostrlogger.go:20:19: undefined: nostr.EncodePublicKey
./nostrlogger.go:34:3: unknown field Type in struct literal of type nostr.Event
./nostrlogger.go:35:3: unknown field Payload in struct literal of type nostr.Event
./nostrlogger.go:39:3: unknown field Timestamp in struct literal of type nostr.Event
./nostrlogger.go:40:3: unknown field Signature in struct literal of type nostr.Event
./nostrlogger.go:40:17: sk.Sign undefined (type string has no field or method Sign)
./nostrlogger.go:45:14: undefined: nostr.Publish
 

 Did you run 

go get github.com/nbd-wtf/go-nostr

? 

 Yes

 undefined: nostr.DerivePublicKey

nostr is never defined anywhere  

 import ... go-nostr should define it. 🤔

Let me try to compile it in termux 

 Looks like your nsec section shoud be like this?

  pk, _ := nostr.GetPublicKey(sk)
    nsec, _ := nip19.EncodePrivateKey(sk)
    npub, _ := nip19.EncodePublicKey(pk) 
 

 Does this compile? 

 It moves on
 Looks like the entite  event section is wrong too. Nothing like the sample   

 Need to read the code for .Publish() to see how to construct the event struct for DM 

 It's KindEncryptedDirectMessage. This is the struct. nip4.go has encryption functions

ev := nostr.Event{
	PubKey:    pub,
	CreatedAt: nostr.Now(),
	Kind:      KindEncryptedDirectMessage,
	Tags:      nil,
	Content:   need to encrypt this,
}