main.py

from odoo import http, tools, _
from odoo.addons.auth_signup.controllers.main import AuthSignupHome


class SolagroAuthSignupHome(AuthSignupHome):
    @http.route('/web/signup', type='http', auth='public', website=True, sitemap=False)
    def web_auth_signup(self, **post):
        # email validation
        if post and http.request.httprequest.method == 'POST':
            email = post.get('email')
            if email and not tools.single_email_re.match(email):
                post.update({'error': _('Invalid Email! Please enter a valid email address.'), 'error_email': True})
            else:
                post["login"] = email
        # name from firstname / lastname
        if post and http.request.httprequest.method == 'POST':
            firstname = post.get('firstname')
            lastname = post.get('lastname')
            post["name"] = firstname + " " + lastname
        # update request params because super() uses this instead of kwargs
        http.request.params.update(post)
        return super().web_auth_signup(**post)