import re

orders = """
Order #A123 amount=450€
Order #B991 amount=1299€
Order #C555 amount=999€
Order #D777 amount=3500€
"""


def get_id_orders(orders: str) -> list[str]:
    pattern: str = r"Order\s+#([A-Z]\d+)\s+amount=(?:[1-9]\d{3,})"
    return re.findall(pattern=pattern, string=orders)


print(get_id_orders(orders=orders))