There are several things you could try if you are not getting a video feed. Please try unlocking the video transmitter ("VTX") per the manual (i.e. hold down the VTX button while plugging in the flight lipo battery). Then, making sure to change the channels via the OSD menu (https://www.youtube.com/watch?v=psFLuiyABZI), please try different bands/channels (your environment may have interference on certain frequencies). Lastly, make sure that your goggles are on the same frequency (band/channel/frequency) as the VTX. Do NOT rely on your goggle's auto-scanning function, as it is notoriously inaccurate and likely to land on a neighboring band/channel.
If the above does not resolve your video issue, please reach out to support. Please note if you are getting only static (potential VTX issue), black screen but with OSD elements (potential camera issue), or black screen only (potential connection or OSD chip issue).