2017 email settings for spf

Hi everybods, sorry for the old subject but i would know what’s an exemple manually spf record for a domain using virtualmin but not as a dns server?

Mails aren’t sent to hotmail mailboxes because there’s no spf record for this domain. I manage my servers still a long time and it works but since a couple of days, i get this error on hotmail.

thank you for any response/help/solution/link

Bye