fix: phoenixd wallet description field supports lnurlp (#2514)

* Fix for phoenixd and lnurlp nostr usage

- Support description, restricted to 128 characters
- Support descriptionHash

Co-authored-by: Pavol Rusnak <pavol@rusnak.io>
Co-authored-by: Vic <vic@example.com>

lnbits/wallets/phoenixd.py

@@ -1,5 +1,6 @@
 import asyncio
 import base64
+import hashlib
 import json
 import urllib.parse
 from typing import AsyncGenerator, Dict, Optional
@@ -17,7 +18,6 @@ from .base import (
     PaymentStatus,
     PaymentSuccessStatus,
     StatusResponse,
-    UnsupportedError,
     Wallet,
 )
 
@@ -87,17 +87,28 @@ class PhoenixdWallet(Wallet):
         unhashed_description: Optional[bytes] = None,
         **kwargs,
     ) -> InvoiceResponse:
-        if description_hash or unhashed_description:
-            raise UnsupportedError("description_hash")
 
         try:
             msats_amount = amount
             data: Dict = {
                 "amountSat": f"{msats_amount}",
-                "description": memo,
                 "externalId": "",
             }
 
+            # Either 'description' (string) or 'descriptionHash' must be supplied
+            # PhoenixD description limited to 128 characters
+            if description_hash:
+                data["descriptionHash"] = description_hash.hex()
+            else:
+                desc = memo
+                if desc is None and unhashed_description:
+                    desc = unhashed_description.decode()
+                desc = desc or ""
+                if len(desc) > 128:
+                    data["descriptionHash"] = hashlib.sha256(desc.encode()).hexdigest()
+                else:
+                    data["description"] = desc
+
             r = await self.client.post(
                 "/createinvoice",
                 data=data,