itch.io

I found some articles that might help you :
https://www.lifewire.com/fix-developer-cannot-be-verified-error-5183898

Especially these points :

3 - If you’re sure you trust the app developer, you can override your security settings and allow the app to install and open.

1. Open Finder.
2. Locate the app you’re trying to open.
3. Control+Click the app.
4. Select Open.
5. Click Open.
6. The app should be saved as an exception in your security settings, allowing you to open it in the future.

4 - Bypass the block in your Security & Privacy settings. If the previous method didn’t work, you can go into your Security & Privacy settings and do it manually.

1. Open the Apple menu, and click System Preferences.
2. Click Security & Privacy.
3. Click the General tab.
4. Click the lock in the lower right corner of the window.
5. Enter your username and password when prompted, and click Unlock.
6. Click the App Store and Identified Developers radial button.
7. Look for “(App Name) was blocked from opening because it is not from an identified developer” and click Open Anyway. (In older versions of macOS, you could click Anywhere and then click Allow From Anywhere.)
8. Try rerunning the app.

5 - Download the app through Safari. If the above process didn’t work, make sure you downloaded the app using Safari. There’s an issue where downloading apps through other browsers, like Chrome and Edge, will cause a problem when trying to install unsigned apps.

1. Delete the app you downloaded through another web browser.
2. Restart your Mac.
3. Download the app using Safari.
4. Try to run the app.
5. When you get the error message, perform the Security & Privacy fix outlined in the previous step.

I hope this will resolve your issue.
Thank you for your patience.