Connection problems tv

[ina0954]

I have a durabrand home cinema system, DBAHT01, When I connect it sky is overriding sound, I can't get it to connect to firestick, I can get sky and tv but no stick, any ideas please my TV is techwood 55AO6USB
PLEASE HELP

 

[hang-the-9]

How is everything wired? Do you have the TV audio out going to the HT system?