Hi @albert TJ
as far as I remember you can create a Chrome Configuration Profile to set this.
https://support.google.com/chrome/a/answer/12129062?hl=en#zippy=
If you use profiles users can probably not change back to another browser as default browser.
Another method is to use the ApplicationDefaults Policy:
https://learn.microsoft.com/en-us/windows/client-management/mdm/policy-csp-applicationdefaults
In this case, you can create an assignment within Windows if Chrome is to be used. In this way, users can also change the default browser back to another browser.