Log in to the Cloudflare dashboard and select an account.
Select your domain.
Go to the DNS.
Click Add record.
Here you will add the TXT record:
Type: TXT
Name: _dmarc
TTL: 60 (1 minute - so that you do not need to wait too long before verifying)
Content: "v=DMARC1; p=none; rua=mailto:rua-import-xxxx@sendforensics.com" [Notes: replace rua-import-xxxx@sendforensics.com with your own unique SendForensics RUA processing address which can be found in Domain Settings for your domain.]
Click Save.
Wait for at least 60 seconds, then you can verify that you have the correct record entered in Domain Settings for your domain.