Use signature encode

ts_src/psbt.ts

@@ -1,6 +1,7 @@
 import { Psbt as PsbtBase } from 'bip174';
 import { Signer } from './ecpair';
 import * as payments from './payments';
+import * as script from './script';
 import { Transaction } from './transaction';
 
 const checkRedeemScript = (
@@ -89,17 +90,12 @@ export class Psbt extends PsbtBase {
 
     const partialSig = {
       pubkey: keyPair.publicKey,
-      signature: keyPair.sign(hash),
+      signature: script.signature.encode(
+        keyPair.sign(hash),
+        input.sighashType || 0x01,
+      ),
     };
 
-    // Just hardcode this for now to satisfy the stricter sig type checks
-    partialSig.signature = Buffer.from(
-      '304302200424b58effaaa694e1559ea5c93bbfd4a89064224055cdf070b6' +
-        '771469442d07021f5c8eb0fea6516d60b8acb33ad64ede60e8785bfb3aa9' +
-        '4b99bdf86151db9a9a01',
-      'hex',
-    );
-
     return this.addPartialSigToInput(inputIndex, partialSig);
   }
 }