2 SQL Servers with High Availability Linux with a shared Witness

Is it possible to have two SQL Always on High Availability servers in datacentre A replicating to two servers in datacentre B with one Witness using Express with two availability groups (one for each server in Datacentre A/B) on Linux? I tried it but I’m having problems so i am not sure if it is what im doing or is it because it cannot be done and I will need two SQL Express Witness servers?