API - Modify options for the registration dialog by the poll admins from public share

[Youcef-Volya]

⚠️ This issue respects the following points: ⚠️

• I agree to follow Nextcloud's Code of Conduct.

Describe the goal you'd like to achieve

As a poll owner/delegate admin, I want to be able to modify the options registration dialog using API request, because it's an important option to get emails from user without account.

Describe possible solutions

No response

Additional context