This tutorial will explain how you can download the free PS5 upgrade for Siren if you already own the PS4 version.
For the first step, you need to go to the PlayStation Store.
Next, you need to select the Search option.
You should then search for Siren.
The search results page should show the PS5 and PS4 versions of Siren listed as Free.
From its product page, select the Download option. Afterwards, select Download PS5 Version.