Hello, the DMARC report you included is indicating that both the DKIM and SPF checks for the received email failed. This can be caused by misconfiguration of DNS settings, your mail provider/SMTP server or someone attempting to send spoofed emails using your domain.
If you are not sending email from an email address on your website domain then someone is spamming/sending unauthorized email using your domain. You can change your existing _dmarc record to v=DMARC1; p=reject; adkim=s; aspf=s; to make it as hard as possible for the spammer to continue using your domain and no longer receive any messages about it. In short, this policy recommends to any server receiving mail from your domain to outright reject it if either DKIM or SPF checks fail. You can also change your SPFTXT record to v=spf1 -all to ensure that the SPF check always fails and mail gets rejected.