Yes, but any phone number will work. That’s irrelevant to the crypto part.

EDIT: (I’m throttled and can’t reply to the child reply) - I said ANY phone number will work. You can get a number from any country, or a VoIP number, or a landline. It doesn’t need to be a sim card from the country you’re in. It doesn’t need to be a sim card at all. Any number will work.

If your country requires details to get a number, get a number from a different country. Unless you’re in China or Russia, we’re on the same internet with the same access to jmp.chat and others.

It is irrelevant to the crypto part, but not when it comes to privacy because as you may know, you cannot just get a prepaid SIM card without your details in many countries, so yeah Signal is not something I would choose.