Uploaded even earlier gdscript implementation.

Euler.gd

@@ -0,0 +1,36 @@
+class_name EulerCalculator extends Control
+
+
+
+func _on_test_button_down() -> void:
+	var answer:int = calc_biggest_palindromic_number(2)
+	show_result(answer)
+
+func _on_calculate_button_down() -> void:
+	var answer:int = calc_biggest_palindromic_number(3)
+	show_result(answer)
+
+func show_result(answer:int) -> void:
+	$VBoxContainer/Label.text = str(answer) 
+
+func calc_biggest_palindromic_number(digits:int) -> int:
+	var highest_palindrome:int = -1
+	var min:int=pow(10,digits-1)
+	var max:int=pow(10,digits)
+	for a in range(min, max):
+		for b in range(min, max):
+			var p:int = a*b
+			var arr:Array = [0]
+			for k in range(1, digits*2+1):
+				var unit:int = p % (pow(10,k) as int)
+				unit /= (pow(10,k-1) as int)
+				arr.append(unit)
+			arr.remove_at(0)
+			if arr.size() != digits*2:
+				continue
+			var is_palindrome:bool = true
+			for k in range(0,digits):
+				is_palindrome = is_palindrome and arr[k] == arr[digits*2-k-1]
+			if is_palindrome and highest_palindrome<p:
+				highest_palindrome = p
+	return highest_palindrome