Not all properties have an internal wall box. Try plugging the cable you can see into the hub to see if it works. Some photos would help us. I expect it is a male F plug on the cable, they don’t make female F plugs. You can get a small female to female connector at B&Q/Amazon to join two cables together.
Tudor
There are 10 types of people: those who understand binary and those who don't and F people out of 10 who do not understand hexadecimal c1a2a285948293859940d9a49385a2