Updated as per changes by @phenax

CNAME records cannot be a full URL. It has to be a hostname. I'd suggest you rename your repo from https://siddpatki.github.io/my-site/ --->> to siddpatki.github.io

domains/sid.json

@@ -6,7 +6,7 @@
     "email": "siddharthapatki@gmail.com"
   },
   "record": {
-    "CNAME": "https://siddpatki.github.io/my-site/",
+    "CNAME": "siddpatki.github.io",
     "URL": "https://sid.is-a.dev"
   }
 }