Using this simple guide, you can register accounts for free on the vast majority of websites that require an e-mail to receive a link to click and a phone number to receive an SMS.
The level of anonymity is inversely proportional to the level of privacy. Basically anyone can log in using your credentials.
How to get e-mail?
I know that smailpro[dot]com just works. In most cases, emails from the sonjj.edu.pl domain are fine. if not - you need to use a gmail email WHICH CANNOT THEN BE OPENED AGAIN. Inbox from sonjj.edu.pl can be opened again.
I'm currently using tmail(dot)link, but this is just the beginning of testing and I can't guarantee equal effectiveness with this tempmail.
I don't know the owners of the first website, the second's are related to TPB. I assume that all these tempail's emails are practically public.
How to get the SMS verification number?
On free websites providing this type of services. It's not about advertising the forum mentioned below, but I just don't want to make it too easy - to find the list, look for BHW and SMS and 2024 on search engine. I guess that it should be enough.
Hint: there should be 12 websites on the free list.
I don't guarantee that every one of these sites works, but some of them definitely do.
PS. For emails, to increase the privacy of your accounts, it is worth using long and random strings of characters as the login part.
PPS. I use this method only for not so important accounts, like this one for example.