Hi I have a TBS QQ190 falcon FPV and I fly it through the DJI RE goggles in analogue mode.
The problem I got is that I cannot find the frequency my VTx emits in order to match them.
I would like to know:
1. whether there is a way to find out the frequency?
2. If the goggles have any other feature apart from auto scan that could pick the freq?

You can select the frequency manually. Go to frequency scanning -> manual -> swipe the touch pad to select the correct frequency. If you don't know which frequency your video tx is using then auto scanning is the best way to find it out. If goggles can't find your video tx make sure that polarization of the tx antenna matches with the antenna you are using on your goggles (the stock DJI pagoda anttenna is LHCP so you will get extremely poor reception if your tx antenna is RHCP).