Google has decided to end all G Suite legacy free edition accounts and move them to paying accounts:
If you have the G Suite legacy free edition, you need to upgrade to a paid Google Workspace subscription to keep your services. The G Suite legacy free edition will no longer be available starting July 1, 2022.
So if you have a Google Workspace or G Suite account free, you will have to upgrade before May 1st 2022.
But, no need to pay full price, you can ask for a discount code of 10% for all of your users!. Ask for it in this link: