Ack frame custom configuration

Hello colleagues!
Tell me please where/how I can configure the Ack frame fields i.e.

“tags”: { // User-provided tags

iside it ?

You will find the tags in the device configuration (web-interface).

Thank you, Orne. found it. and it worked!
Another one question.
Can I dynamicaly change the user-provided tag values, on the fly, before sending? i.e. insert current time as value of “key” field, for example ?
“tags”: { // User-provided tags (optional)
“key”: “value”

No, that is not the intended usage of this feature.