Eman, if you have the VC Encore the 6" probe is fine it will stick out the back a little but you can support it with the hardware VC included with their temperature gauge. I had some thing metal "string" I wrapped it around just to make sure it stays in place.I see your probe tip is about the center of the catalyst. I will see if I can find a thermocouple probe that's a right angle style that won't stick out as far. There's nothing on the back of my stove to support it.
@Jason79er see attached pictures. Also, I linked what you need to buy below to the AUBER website, courtesy of @Woodsplitter67
https://www.hearth.com/talk/threads/2022-23-vc-owner-thread.193685/post-2608952
![[Hearth.com] Help with VC Encore Cat Probe/Thermometer [Hearth.com] Help with VC Encore Cat Probe/Thermometer](https://www.hearth.com/talk/data/attachments/301/301072-1f9b95d5355034459b115a11fb81a83a.jpg?hash=CWogQn85RW)
![[Hearth.com] Help with VC Encore Cat Probe/Thermometer [Hearth.com] Help with VC Encore Cat Probe/Thermometer](https://www.hearth.com/talk/data/attachments/301/301073-87c44c52771736a782aec45297ac69a3.jpg?hash=vc-RAf3-Xo)