Hey, @evno0244 !
Welcome to the Community and thanks for reaching out about this.
It sounds like your domain was unexpectedly disconnected from your account. Therefore, as the first step towards troubleshooting, please try adding it back by going to ‘Online Store > Domains > Connect existing domain’.
Enter your purchased domain name in the box as seen below, and click Next to proceed with the connection.
This should now reconnect it to your account, and you’ll then see it listed on your Domains page in your Shopify admin. Please note, your domain may initially have a notification next to it saying ‘Setup in progress’ or ‘SSL pending’. These should resolve within 48 hours of re-establishing the connection.
Let me know how it goes!