My Acer Nitro V-15 ANV-1551 on the Nitro Sense App, displays these temperatures while gaming?

Looks normal. It's normal when GPU/CPU temperature are below 90°C but good temperatures are 70°C to 85°C which can be achieve by optimized settings and providing proper for flow to your laptop. If temperature are reaching 90°C then it's not good.

Sometime when summer season is going on or weather is hot at that time electronics heat alot in which can't do much but try to keep temp acceptable using some tips like i shown below.

Here some tips-

solutions-
1)Fps cap 
Capping fps to lower value like 60, 100, 120, 140, etc can greatly lower cpu temperature and keep cool
(Cap you fps through Nvidia software or use RTSS)

2)Prop the laptop up with books around the sides to reduce heat
Grab stack of 2-4 books that are equally thick. Slide the spine of a book 2–3 inches (5.1–7.6 cm) under the right side of the laptop. Do the same on the left side of the laptop.

[You can also Buy good cooling pad in which stands are inbuilt, its better than books]

3)You can follow this below guide completely to reduce Cpu load and increase game performance-
Windows 10/11 optimization guide for gaming — Acer Community

In case You don't know all laptops/pc need proper maintenance after 1 year of gaming.

(Need to clean fans, air vents and apply new good quality thermal paste to keep performance as new and reduce temp)

In future time may come when you can't control temperature and you need to do this.