Fix DNS & Reconnect Klaviyo to Shopify

I need help resolving a DNS issue that's causing my website to be down. I've made no recent changes to my DNS settings or website configuration, and I haven't been able to contact my domain registrar or hosting provider for assistance.

Key Tasks:
- Diagnose and fix the DNS issue preventing my site from loading.
- Reconnect Klaviyo to my Shopify store to ensure everything is operational again.

Ideal Skills & Experience:
- Strong knowledge of DNS settings and troubleshooting.
- Experience with Klaviyo and Shopify integration.
- Ability to resolve issues without direct support from domain registrars or hosting providers.

Please provide a brief overview of your approach and relevant experience.