DKIM for email

[KangJL]

Free hosting does not support DKIM record.
If you can add your domain to CloudFlare, then it may be possible.
You can only do this if you own a custom domain

More info below

Can I create DKIM records on free hosting

To reliably authorize a specific email provider to send emails on behalf of your domain, you should configure both SPF and DKIM records for your domain name. While SPF records can be configured through the SPF Records section, configuring DKIM records requires a different approach. No support for TXT DKIM records InfinityFree’s free hosting nameservers do not support setting DKIM records directly. Additionally, free hosting does not support custom TXT DNS records, making it impossible to set u…