"No heartbeat packets recieved" error in telemetry connection

Hello everyone;
I’m trying to connect radio telemetry to the mission planner on my computer but I couldn’t because I get the “No heartbeat packets received” error after 30s time out the connection. The air module is connected to TELEM 1 port - pixhawk and the lights of both of them are solid green lights which means they are connected correctly. I don’t know why I can’t connect the radio telemetry to my computer.
I attached the image with my setting parameters to my telemetry connection.

Any help with this would be greatly appreciated.
Thanks in advance.

Check the TX, RX wiring.

which hardware do you use? please tell me hardware configuration and your arduino or embedded experience

FC MCU TX should be connect to Telemetry MCU RX

Serial port protocol set to Mavlink2? This is the most common reason it doesn’t work.

You are on old firmware but that shouldn’t prevent it from working. And some get themselves in trouble by updating the ground radio and not knowing how to update the air radio. Unless the Air radio has a USB port then it’s simple. Some do, some don’t.

Did you fix this issue? I am having a similar problem with telemetry radios