First you need to get the OID values.
Here is what I used:
SNMP Value – Internal Temp: 126.96.36.199.4.1.21188.8.131.52.1.5.1
SNMP Value – Internal Humidity: 184.108.40.206.4.1.21220.127.116.11.1.6.1
SNMP Value – Internal Duepoint: 18.104.22.168.4.1.2122.214.171.124.1.7.1
In PRTG setup a custom SNMP sensor and use the related IOD above. Important!!! These are for SNMP V2, make sure your sensor is SNMP V2 or it will not work.
On the Internet Temp and Dew Point ones setup the Division by 10, you can keep the divison 1 on the Humidity.
If all goes well you should see something like this:
Any questions let me know.