The first thing to check is that your Caltrics Subscribed calendar hasn’t been turned off. Do as follows:
Tap the Calendar app on your iPhone/iPad and then click on Calendars. Underneath the heading SUBSCRIBED, you should see Caltrics and this should be selected. If it isn’t, select it and the events from all the Caltrics internet calendars you have selected will appear in your iPhone/iPad calendar in approximately 15 minutes (you can also do the same by going Settings/Passwords & Accounts/Subscribed calendars/Caltrics and then check slider is on).
If there is no SUBSCRIBED calendar heading or a SUBSCRIBED heading with no Caltrics listing, do per the following link:
I have a Caltrics account and have calendars selected but events are not appearing in my iPhone (iPad/iOS) calendar