I've had internet contacts with various banks for years and used to receive TANs in paper form for transactions, but more recently via SMS to my registered older-style mobile phone. Everything worked or still works without complaint.
Now, however, I'm told that in the foreseeable future TAN's are likely to be transmitted only via APP, for their receipt but a smartphone should be required. However, since I put absolutely no value on the other benefits of these novel smartphones and therefore I would like to save both the acquisition and the operating costs, I ask the question of whether there's not a way, the relevant APP's easy on my PC or my laptop convenient to load.
May I ask the experts for advice?
You have to ask your bank.
Generally, you will not be able to easily install the app on your PC. But often banks offer alternative methods, HBCI is mine one. With chip card and reader.
But ultimately you have to ask your bank what they support. If this is just App-TAN, then you will not be able to get around a cell phone (or you will have to change the bank).