diff --git a/lnbits/extensions/satspay/templates/satspay/index.html b/lnbits/extensions/satspay/templates/satspay/index.html
index fd8cf1ec..9691572a 100644
--- a/lnbits/extensions/satspay/templates/satspay/index.html
+++ b/lnbits/extensions/satspay/templates/satspay/index.html
@@ -767,7 +767,7 @@
         this.createTheme(wallet, data)
       },
       sendFormDataCharge: function () {
-        this.formDialogCharge.data.custom_css = this.formDialogCharge.data.custom_css.id
+        this.formDialogCharge.data.custom_css = this.formDialogCharge.data.custom_css?.id
         const data = this.formDialogCharge.data
         const wallet = this.g.user.wallets[0].inkey
         data.amount = parseInt(data.amount)