If the error persists after verification:
If you are using a non-Steam version, the crack, which replaces steam_api.dll with a custom version, might have been removed by Windows Defender. How to Safely Fix the steam_api.dll Error (Best Methods)
Trying to launch only to be stopped by a "steam-api.dll missing" error is a classic headache for many players. While it might be tempting to just search for a quick "download" link, that path often leads to more trouble than it's worth.