[luuurker]

Without "SIM card" and "without a number" are different things. Apparently you still need a number, a "blockchain-powered" number:

"[...] You can have a Telegram account without a SIM card and log in using blockchain-powered anonymous numbers available on the Fragment platform."

[OSI-Auflauf]

Irs super complicated to use. And you need an existing Telegram account to actually handle that cryptocurrency to buy these pseudo-numbers outside of the telephone namespace. Guess what you need to register those. An actual working phone number.