You can find physical copies of the PC version or console versions on sites like Amazon or eBay . Prices for used copies can vary significantly, sometimes ranging from $40 to over $90 depending on the platform.
Since you cannot download it from official stores, you have two primary options: Spider-Man Web of Shadows Free Download
While some sites offer "free" versions, these are often unofficial and can pose security risks. You can find physical copies of the PC