I am trying to install the square app on my iPhone, but it requires a Touch ID. No instructions.

[IB]

Installation of the app requires Touch ID.  There is a round fingerprint symbol and when I touch it, nothing happens.  I am unable to install the app.

[VanKalkerFarms]

That sounds like an issue with the way you have your phone set up to make purchases (even free ones) through the app store. Do you normally use Touch ID to make purchases or unlock your phone? You can control Touch ID in the Settings menu of your phone. You can try restarting the App Store or your phone if you have Touch ID set up but your phone just isn't accepting your fingerprint.