You can enter SPF records using the TXT record type in the DNS settings in your Dynadot account. To set an SPF record, please follow these steps:

1. Sign in to your Dynadot account.
2. Select "My Domains" from the left-side menu bar and click "Manage Domains" in the drop-down.
3. Check the box next to your domain name(s) and click on the "Action" button.
4. Choose "DNS Settings" from the "Action" list.
5. On the DNS page, select the "Dynadot DNS" setting from the top drop-down menu.
6. If you have been instructed to set a host name other than "@," please add the record under "Subdomain Records" and enter the host name as a subdomain. (If the host name is "@," the record should be entered under the "Domain Record" section.)
7. Select "TXT" from the drop-down menu.
8. Enter the information for your SPF record in the "IP Address / Destination" box.
9. Press the "Save Settings" to save your changes.

Setting SPF records can help prevent spammers from sending messages with forged from addresses at your domain.

Want to add more DNS records? Please check the guideline here.