Slider Automation

I’m trying to make an automation that sends a slider value to a MQTT topic, so far I can get it send to the the topic but its sending the name of the entity not the value, is it possible to send the slider value to a topic?

under action in the automation this is what
{
“payload”: “input_number.post_dimmer”,
“topic”: “Keaster_Home/outside/LED_PWM”
}

but what gets published is input_number.post_dimmer I need the value of that slider

Thanks.

Try
"payload": "states.input_number.post_dimmer.state"