There is no feature that prevents users from changing their own Password.
If administrators want to reduce the burden of Password management, please consider operations such as limiting the Login method to Single Sign-On only.
Related: Configure Single Sign-On (Web Browser)
https://teachme.jp/8/manuals/51167186
Related: Limit Login to SSO / Remove Limit (Web Browser)
https://teachme.jp/8/manuals/51167209