odoo-survey-addons/survey_pass_fail_messages/models/survey_survey.py

from odoo import models, fields, api, _
from odoo.exceptions import UserError


class SurveySurvey(models.Model):
    _inherit = "survey.survey"

    description_done_pass = fields.Html(
        string="Passed end message",
        translate=True,
        help="This message will be displayed when survey is completed and the user passed the test.",
    )
    description_done_fail = fields.Html(
        string="Failed end message",
        translate=True,
        help="This message will be displayed when survey is completed and the user failed the test.",
    )