Change mqtt 'update_period' variable

I'm trying to update the update_period variable in the mqtt settings. According to documentation https://shelly-api-docs.shelly.cloud/#common-http-api I need to send a POST request with url parameters. I tried doing this 192.168.33.1/settings?update_period=1 but it changes nothing. Does anyone have an idea how to do this?

turns out I needed to use mqtt_update_period instead

Hi,

I bought my shelly 3em recently. I have updated the mqtt_update_period to 1s. Do you know how to configure the payload? i need to have timestamp in it .