[Bug] The possibility of registration without filling in the last name field

[Nat754]

Preconditions: If necessary

Reproduction steps:

1. Open the page https://brainup.site/
2. Click the button "Registration"
3. Fill in the field Last Name and First Name only Last Name
4. Fill in the other fields with the correct data
5. Click the button "Registration"
   Expected Result:
   There is validation message Empty Last Name and user is on the registration page - registration unpossible.

Actual result:
There is validation message "Empty Last Name", but user has been registered. The profile has empty fields.
Application:

2026-03-15.15.20.17.mov

Environment:

• OS: [iOS]
• Browser [chrome]
• Version [145.0.7632.160]

Additional context: Add any other context about the problem here.