MacOS has built-in protection against apps downloaded from the internet.
You download Coach 7 from our website. Once you have installed Coach 7, you must indicate that you trust this software.
Go to the application folder in a finder window.
Right-click on the Coach 7 icon and choose Open. (You can also hold down the CTRL button and then choose Open).
Indicate that you trust the program. Coach 7 will now open. You only need to perform this action once.
You can achieve the same by indicating in System Preferences -> Security & Privacy -> General, that you trust the Coach 7 app.
Here you will find the explanation from Apple.