Setting up Google Workspace with New Domain

I have just created a new website in Squarespace named 'maldivesmantaconservation.org', using a domain I purchased through Hover.

This website is managed through the Manta Trust Squarespace account.

Both 'Manta Trust' and 'Maldives Manta Conservation Programme' are registered charities, and work in collaboration, however Manta Trust is the only charity that currently has a free Google Workspace for Non-Profits account. This means that all charity team members of the Manta Trust have an email address like so: name@mantatrust.org.

I want to set up the same thing for Maldives Manta Conservation Programme staff, so that they have email addresses that link to the domain name eg. name@maldivesmantaconservation.org.

When I go to set up a Google Workspace plan for the domain 'maldivesmantaconservation.org' through Squarespace it automatically goes to charge me. So first I need to apply for the Google Workspace for Non-Profits account for Maldives Manta Conservation Programme. However, in order to do this I have to show that I have a google account first. Therefore, do I buy one email account with Google Workspace through Squarespace first?

Currently confused at the steps I need to go through. Thanks in advance.