Dear Vanditha,
Thanks for your updates.
If you can't access Microsoft Forms outside your office, it may be that a condition access policy set only the office devices IP for users to access Microsoft Forms.
You may go to the Microsoft 365 Azure AD admin center>Protect & security>Conditional Access>Policies>check whether there is such a policy.
If yes, click on and edit some properties such as Conditions>Locations based on your environment, wait some time and then do a test again to see the result.

If you can't get that, it may be that you don't the full administrator role, you may contact a global administrator to do that.
Thanks for your effort and time!
Sincerely,
Cliff | Microsoft Community Moderator