To point your domain to Tumblr, you need to configure custom resource records in the Google Domains console.
Here are the steps for domain pointing with tumblr :
On Google Domains, click the configureDNS tab.
In the Customresources records menu, create an A record for the root domain <@> and enter IP 66.6.44.4 in the data field then click Add.
Create a CNAME record for www and point to domains.tumblr.com then click Add.
An example as shown below:
Then, configure your domain on Tumblr:
1. On Tumblr, click Settings under the Account menu.
2. Click the blog you want to update on the right side of the page.
3. Click the pencil icon to the right of the Username section and enable Use a custom domain.
4. Enter your domain (e.g. domainanda.com) or your subdomain (e.g. www.domainanda.com).
5. Cliick Test your domain.
6. Click Save.
Note:
Please note that DNS changes take a few minutes to propagate, depending on your location, the propagation process may take 24-48 hours.