Ensure the mod is built for Repentance or Repentance+ . Older mods for Afterbirth+ (AB+) may still work, but those specifically for the Repentance era are more stable.
Since you aren't using the Workshop directly, you will need to find the mod files elsewhere. Community members often use third-party downloaders or find projects on GitHub or Nexus Mods. the binding of isaac repentance mods no steam updated
To get the most out of your run without the Steam Workshop, look for these highly-rated, frequently updated mods: Ensure the mod is built for Repentance or Repentance+
Perhaps the most critical mod, it provides detailed text for items, trinkets, and cards directly on-screen so you don't have to pause to look them up. look for these highly-rated
For Repentance on Windows, the default directory is typically found in Documents/My Games/Binding of Isaac Repentance/mods .