First head to：https://account.microsoft.com/profile, register a Microsoft account. If you already have one, you can skip this step and just login.
Apply for developer account
Then head to：https://developer.microsoft.com/en-us/office/profile/ and login to apply for the developer account. Fill up the country, company name and language preference, then click Next
It will then ask you some questions about your working industry and area of interest. You can select base on your own situation.
After filling all up, click Next
Then select SET UP E5 SUBSCRIPTION；Choose your country, username, domain and password, click continue once finished. Fill your phone number and get the authorization code.
After set up, wait a moment then you will see your Microsoft 365 E5 developer subscription has been activated.
Microsoft 365 E5 subscription includes lots of services. Like Office 365 desktop program and Onedrive etc.
You can use your account end with
onmicrosoft.com to login to：https://portal.office.com/ to manager your subscription.(Not your personal Microsoft account)