...
Login into TPH SharePoint using the email address where the invitation was sent.
If you have a company email address you will usually need to select ‘organisational account’ and then use the same username and password you would use to sign into your company email account.
If you are using a private email address (eg gmail), you will either need to use your person Microsoft Office password
if you have an account for that email address, or sign up for a free account using the same email address where you received the SharePoint invitation.
You will be prompted for setting up MFA as shown below in the picture.
...