Problems getting Mag enabled on Beitian 880 GPS Module on Omnibus F4 V6

Tried it just now, receiver does not seem to connect, i have soldered SBUS wire to TX2, Smart Port is on SoftSerial1, telemetry seems to work but SBUS does not. Changed port mapping to UART 2 for SerialRX. any other work around or am I doing something wrong here? Also did not see any TX4 pin layout, where is it located?