Log into your Cloudflare dashboard ↗ where you purchased your domain and create a new CNAME record by following these steps:
Select your account and domain.
Go to DNS > Records.
Select Add record.
Choose a record Type as "CNAME"
Type "www" for the Name field.
Type "custom.zarlasites.com" for the Content field
Turn off the Cloudflare proxy if it's on by default, but leave the other fields on their default settings.
Select Save.
Then, find one of your existing A records in Cloudflare:
Make sure you're still on DNS > Records.
Find a record with an "A" in the Name field, and click Edit to make changes
Make sure the "Name" field shows the "@" symbol
Change the Content field to "109.105.219.109"
Turn off Cloudflare proxy if it's on, but leave the other fields on their default settings.
Select Save.
Lastly, find the final record with an "A" in the Name field and delete it. You only need one "A" record with Zarla.
Once you've finished all those steps, please let us know. We'll check that everything is pointed correctly and then set your domain live.