How to redirect older url to newer url to manage subscriptions

Hope the author or someone is able to help as I’m seeing others having similar 404 errors with no solutions offered.

Links to the virtual subscription page are resulting in 404 because page management URL is https://mywebsite/manage-subscriptions/comment-subscriptions/etc but old management URL before an update were setup to point to https://mywebsite/comment-subscriptions/etc.

So now thousands of old subscriptions link to dead links because they are missing /manage-subscriptions/ while thousands of new subscription links work perfectly.

How do I append /manage-subscriptions/ in the older subscription links?

Thank you for your support