Added in a new file to store the list of JWT algorithms that can be used, as this error was occurring due to a mismatch between what you could sign and what you could verify

src/core/lib/JWT.mjs

@@ -0,0 +1,24 @@
+/**
+ * DateTime resources.
+ *
+ * @author mt3571 [mt3571@protonmail.com]
+ * @copyright Crown Copyright 2020
+ * @license Apache-2.0
+ */
+
+
+/**
+ * List of the JWT algorithms that can be used
+ */
+export const JWT_ALGORITHMS = [
+    "HS256",
+    "HS384",
+    "HS512",
+    "RS256",
+    "RS384",
+    "RS512",
+    "ES256",
+    "ES384",
+    "ES512",
+    "None"
+];