diff --git a/lnbits/core/templates/core/_api_docs.html b/lnbits/core/templates/core/_api_docs.html
index c7f3f9ad..0e74f38e 100644
--- a/lnbits/core/templates/core/_api_docs.html
+++ b/lnbits/core/templates/core/_api_docs.html
@@ -61,7 +61,7 @@
         <code
           >curl -X POST {{ request.base_url }}api/v1/payments -d '{"out": false,
           "amount": &lt;int&gt;, "memo": &lt;string&gt;, "webhook":
-          &lt;url:string&gt;}' -H "X-Api-Key: <i>{{ wallet.inkey }}</i>" -H
+          &lt;url:string&gt;, "unit": &lt;string&gt;}' -H "X-Api-Key: <i>{{ wallet.inkey }}</i>" -H
           "Content-type: application/json"</code
         >
       </q-card-section>
diff --git a/lnbits/core/views/api.py b/lnbits/core/views/api.py
index 107a2684..a5358275 100644
--- a/lnbits/core/views/api.py
+++ b/lnbits/core/views/api.py
@@ -123,7 +123,7 @@ async def api_payments(wallet: WalletTypeInfo = Depends(get_key_type)):
 
 class CreateInvoiceData(BaseModel):
     out: Optional[bool] = True
-    amount: int = Query(None, ge=1)
+    amount: int = Query(None, ge=0)
     memo: str = None
     unit: Optional[str] = "sat"
     description_hash: Optional[str] = None