Your Google Form setting requires LOGIN before it will even DISPLAY the form on your website… meaning only your institution’s users who are logged in to their Google Workspace organization account can even see the form.
This is the reason for the “security header DENY error” that Liew mentioned above, as Google’s login page cannot be embedded in an iframe on any random domain.
Kindly get your institution’s IT support folks to change the form’s setting to allow DISPLAYING and FILLING the form outside the organization. Note that this might require making changes in the institution’s Google Workspace security policy, if not allowed at the organization level already.
You may pass this official Google support documentation to IT support: https://support.google.com/docs/answer/160166?hl=en
Good luck!
UPDATE:
If you need further proof of this, kindly open a new Guest, Private or Incognito browser window (where you’re not logged in to your institution’s Google Workspace account at all), and try the following two links:
Direct link to your form (picked from your website): https://docs.google.com/forms/d/e/1FAIpQLScAu-RnBSXZ6FSWo4DXt509Ma8mJJYnjFp2CGGUKxExCs3cXw/viewform
Direct link to a test form I just created: https://docs.google.com/forms/d/e/1FAIpQLSeWvTqvzYVLHyHRWB1XjMFgJFVhDgkO3GsAAqPJVcdUotnvpw/viewform
As you can see, the first link (your form) takes you to a Google login page, asking for a login before the form can be displayed. This is why your form is not working on your website.