Website Alias Stopped Working

HI - We've had the same website alias, masontowncriers.org for years. Last Thursday or so, it stopped working. I have verified that 5008.toastmastersclubs.org/ works to get to our website.
It looks like our alias is in fact a custom website domain, which isn't pointing to the right IP address, but I'm lost in trying to change that. I get the following error message:
Basic Settings Tab - This domain is not yet pointing to the IP address 50.19.253.65. In your domain registrar's DNS area, modify the existing "A" and "MX" records for this domain, to point to 50.19.253.65, wait the amount of time as specified by your domain host, then try again.

Would someone help me update my DNS IP address? At this point, I'm in a little over my head. Thanks!

masontowncriers.org is a custom domain and was purchased by a member of your club.

The person who purchased the domain needs to contact the registrar network solutions, sorry but we cannot assist with this.

Domain Name: MASONTOWNCRIERS.ORG
Registry Domain ID: D107031243-LROR
Registrar WHOIS Server: whois.networksolutions.com
Registrar URL: www.networksolutions.com
Updated Date: 2020-07-30T09:45:51Z
Creation Date: 2005-07-28T15:27:33Z