I can't sign up with my personal email address
The free trial can only be started with a work email on your company's domain; personal and temporary addresses aren't accepted.
You can only sign up with a work email. Personal addresses such as gmail.com, hotmail.com, outlook.com, yahoo.com, yandex.com and icloud.com, and temporary email services, aren't accepted.
When you enter a personal address, the warning “Please use your work email.” appears under the “Work email” field and the “Start free trial” button stays gray.
The rule only looks at the part of the address after the @ sign. An address on your company's own domain (e.g. name@company.com) is accepted; it doesn't matter which business email service hosts your mailbox.
If you don't have an address on a company domain, you can't start a trial from the sign-up form.