There are several ways to find the installers you need for your Redgate tools.
Log in to the customer portal
You can access the details of your Redgate licenses by logging into your Redgate account on our website.
The first view you see in the My Products tab shows a summary of all the licenses associated with your account and you can download the latest versions of your tools from here.
On your invoice
When you purchase a Redgate license the download link for the installer is on the invoice.
On the Redgate download site
You can find installers for all the product versions you require, current or older versions, here:
NB: If you're looking for SQL Monitor installers they are under https://download.red-gate.com/checkforupdates/SQLMonitorWeb/, not SQL Monitor.