Connection exceeded alert.

I have been trying to find a steps or solution for past 1 year once we received a connection exceeded alert. Couldn't get any answer from anybody or internet so far.

Today I checked a pgbadger report and  matched the timeline and found that, at that time of sudden connection hike (not normal), there were 3 queries running at that time (2 update queries on table a , took 5s each, one insert query on table b which took 2.5mns).

Anybody provide me steps what all I have to do 1. At that time of connection hike 2. If I am been asked to check after sometime as connection dropped to analyse.