I tried three or four times to join Parler using the Parler app. I got to the Captcha page and put in the code (which was not hard to decipher, unlike some Captchas) and it said it was wrong. I loaded it again, different captcha, still said it was wrong.
I don’t have a smartphone ..I use a laptop ..can’t help I’m afraid. Maybe contact them somehow?
https://home.parler.com/contact/