Easest way to control light with switch

I use OH4, I have 2 channels: switch and contact. Contact is real wall contact, switch is output to control light via relay. I have 2 items and rule like when switch is on we need on light and visa verse. Is it possible to avoid rule and control light directly from contact?

Have a look at „follow“ profiles:

I didn’t find way how follow can help me. I have 2 MQTT channels:

  - id: MQTT_ST_IO13
    channelTypeUID: mqtt:contact
    label: Label IO13
    description: Label IO13
      stateTopic: iot/st-iot-1/event/13
      off: "0"
      on: "1"
  - id: MQTT_ST_IO4
    channelTypeUID: mqtt:switch
    label: Label IO04
    description: Label IO04
      commandTopic: iot/st-iot-1/command
      off: '{ "pin": 4, "state": 0 }'
      on: '{ "pin": 4, "state": 1 }'

One channel linked to wall switch, second to lightbulb. I don’t see how to connect these 2 items without rule. Open/Closed state should be send as On/Off to switch. Is it possible implement this behavior without rule?

First of all, create an item for each channel.
Go to Things - Channels - Click on the item and you will see at the bottom that you can select a follow profile. However, I do not know how to proceed further as I do not need follow profiles. But this profile is exactly what you need.
You could also try to link your light item to the switch channel. Not sure right now if this might lead to any problems.

I can’t link contact to switch, OH doesn’t allow do it in UI. I able to select profile during link item to channel, but as result I have 2 items linked to own channel. I don’t see how to connect 2 items without rule.

Contact is a read-only item type.
Did you try to link the switch item (light) to the contact channel (wall switch)?