how to install DKIM & SPF for sending emails from zoho mail servers with my zoho admin login?

how to install DKIM & SPF for sending emails from zoho mail servers with my zoho admin login?

Hi

send emails from app 
recipient's mail servers say that email was send from untrusted domain and mail servers can't check trust of sender's domain

zoho admin login is from "@yandex.ru" mail domain and email sent from zoho mail servers

recipient's mail servers say that i need install DKIM and SPF 

how to solve this task, so that recipient's mail servers will trust my emails?