Ok, so you didn’t have to use a cellphone to get the sign up code?
Did they email it to you?
I was sent a Truth Social verification code as after message to my phone. I am not sure there is an alternative solution for that issue.
I wonder if the free texting numbers you can get at sites such as https://textfree.us would work to get on Truth Social? I do all of my texting using that one, from my PC. You could try it and find out. I think I had to have a portable device to sign up for TextFree, but I used my tablet on WiFi just to do that. I didn’t have to try using my texting number to get on TS, because my Tracfone flip phone, which has my only mobile number, receives texts (although it’s a pain to actually text on it with the numeric pad). BTW, Truth Social never asked me for any email address at all.