Cash app is reliable for smartphone as well as computer to make an online payment. You can easily access it on your computer from anywhere by putting the corecrt userís credentials. If you are not able to access Cash app on computer, then try to reload or refresh the current webpage and also check the internet connection. You have to make sure that you logged in your account by providing the correct userís credentials or select the correct mode of payment. If you still unable, then use Cash app customer service.