If you are a ChatGPT enterprise customer, then your site is chatgpt.com.
If you are on a company domain and using a company email address is what got you access, you would NOT want to fund an API account there with your own money for experimentation, as loss of company access would make your personal credits and whole account be inaccessible.
You also might have been asked to “migrate” your ChatGPT to Enterprise, in which case the company is now all up in your ChatGPT business, but the API should still be yours if it was created with your own email and password.