Link domain to google site

I am trying to link my domain to a google site that already exists. I have followed all the steps accurately to change my DNS settings to accomplish this. It's not working, and the Squarespace team keeps saying I am missing the (.) at the end of the ghs.googlehosted.com in the CNAME setting. I have added it multiple times by editing and saving and also deleting and re-adding the setting. THE (.) will not save at the end. PLEASE HELP!!