feat: Allow custom memo on pay invoice (#3236)

Co-authored-by: Vlad Stan <stan.v.vlad@gmail.com>

lnbits/static/js/base.js

@@ -20,22 +20,35 @@ window.LNbits = {
       memo,
       unit = 'sat',
       lnurlCallback = null,
-      fiatProvider = null
+      fiatProvider = null,
+      internalMemo = null
     ) {
-      return this.request('post', '/api/v1/payments', wallet.inkey, {
+      const data = {
         out: false,
         amount: amount,
         memo: memo,
-        lnurl_callback: lnurlCallback,
         unit: unit,
+        lnurl_callback: lnurlCallback,
         fiat_provider: fiatProvider
-      })
+      }
+      if (internalMemo) {
+        data.extra = {
+          internal_memo: String(internalMemo)
+        }
+      }
+      return this.request('post', '/api/v1/payments', wallet.inkey, data)
     },
-    payInvoice(wallet, bolt11) {
-      return this.request('post', '/api/v1/payments', wallet.adminkey, {
+    payInvoice(wallet, bolt11, internalMemo = null) {
+      const data = {
         out: true,
         bolt11: bolt11
-      })
+      }
+      if (internalMemo) {
+        data.extra = {
+          internal_memo: String(internalMemo)
+        }
+      }
+      return this.request('post', '/api/v1/payments', wallet.adminkey, data)
     },
     payLnurl(
       wallet,
@@ -44,16 +57,28 @@ window.LNbits = {
       amount,
       description = '',
       comment = '',
-      unit = ''
+      unit = '',
+      internalMemo = null
     ) {
-      return this.request('post', '/api/v1/payments/lnurl', wallet.adminkey, {
+      const data = {
         callback,
         description_hash,
         amount,
         comment,
         description,
         unit
-      })
+      }
+
+      if (internalMemo) {
+        data.internal_memo = String(internalMemo)
+      }
+
+      return this.request(
+        'post',
+        '/api/v1/payments/lnurl',
+        wallet.adminkey,
+        data
+      )
     },
     authLnurl(wallet, callback) {
       return this.request('post', '/api/v1/lnurlauth', wallet.adminkey, {