If I'm not mistaken you are searching for a way to control your fan, right ?
I also use AMD graphics (Radeon RX 570/16G) so I can show you what I did to keep temperatures within my preferred range.
Keep in mind though that since your GPU (Radeon RX Vega 6) and CPU (AMD Ryzen 5) are integrated in one chip (APU) you probably only have a CPU fan and not a separate GPU fan like I have.
Also, know that the Ryzen family of CPUs and GPUs can stand temperatures of up to 94°C ( 200°F )
(although I myself would not let the chip exceed the 85°C by much)
I don't have any Ryzen APU at hand so I can not test it for you, so I hope the following text will be of any help to discover the things you're looking for.
This is what I did on my system to discover how I could influence the thermals:
$ for line in /sys/class/hwmon/hwmon* ; do echo $line ; cat $line/name ; done
/sys/class/hwmon/hwmon0
nvme
/sys/class/hwmon/hwmon1
amdgpu
/sys/class/hwmon/hwmon2
nct6797
/sys/class/hwmon/hwmon3
k10temp
/sys/class/hwmon/hwmon4
hidpp_battery_0
which tells me that values under /sys/class/hwmon/hwmon1 are considering the GPU
further invoking
$ ls -1 /sys/class/hwmon/hwmon1 |grep fan
fan1_enable
fan1_input
fan1_max
fan1_min
fan1_target
tells me that fan1 is the GPU fan.
The current rpm of the fan is made visible by invoking:
cat /sys/class/hwmon/hwmon1/fan1_input
To control the fan, you need to write values to its pwm input
First find out which controls you have:
ls -1 /sys/class/hwmon/hwmon1 |grep pwm
pwm1
pwm1_enable
pwm1_max
pwm1_min
If you succeeded so far you might take a look at this AMD documentation
And since I use my own script to regulate the speed of the fan, the following post might be interesting for you:
Or you might try another piece of software for controlling your fan: