transparent proxy, with parent proxy

RouterOS General
1

I have squid proxy allready configured on my LAN… When I set Mikrotik’s web proxy to use thath proxy as parent proxy it works, but how to make transparent proxy ?
squid adress: 192.168.0.254 port 3128
MT: 192.168.0.250 port 8080

I tried to redirect port 80 to-dst port 8080 in dst NAT and check “transparent proxy” under web-proxy but then I get error from browser “Access denied…”.

Thanks !