Depends where you buy it. The 49€ ticket is to be precise not a ticket. But a regulations stating that transport providers have to provide tickets for the cos

Depends where you buy it. The 49€ ticket is to be precise not a ticket. But a regulations stating that transport providers have to provide tickets for the cost of 49€ valid all across Germany (very strongly oversimplified). This means there are many places selling this ticket which only are the same in where it's valid, how much it costs, and how it can be validate by any arbitrary public train service. So some providers sell chip plastic cards with a NFC chip in them and some ID+Name+Date printed on it which get shipped to you. Other provider only sell it through the App using your phones NFC chip or (I think, not sure) QR as fallback. Similar some might only accept SEPA payment mandates (i.e. implicitly require and EU bank account) and require you to have an German address to ship the card to. Other require SEPA and hand it to you personally not caring about an address in Germany and others might accept Google Pay, Apple Pay or Paypal and are online only. While this sounds bad, for most German people this is a complete non issue as they just buy it form the same transportation provider they used before using the same payment method they where using before. (The reason this works technically is because there already was a system for validating tickets valid in the transport net of one provider issued by another, most commonly DB long distance tickets also covering public transportation around the time of arrival/departure).