Hi
The attr_write requires the attribute type (an unsigned 8 bit number).
In your case it an uint8 - which is cod 0x20 or 32 in decimal.
service: zha_toolkit.execute
data:
command: attr_write
# You could replace this with the entity name if you like:
ieee: cc:86:ec:ff:fe:d8:43:b6
# Endpoint can be omitted if there is only 1 cluster of the given type on the device
endpoint: 1
# A bit suprised that cluster 0 is used for enabling/disabling a siren, but that's the doc.
cluster: 0
# Ok, you could also write this directly as 0x400a
attribute: 16394
# Ok, you cuould also omit the quotes
attr_val: '1'
# The type is required when writing
attr_type: 0x20
# The attribute is manufacturer specific - fill in th emanufacturer id.
manf: 0x????
# Optioinal, setting an event to get an idea of what happened from the UI.
# You can "Listen" to the 'my_write_event' from Developer Tools > Events
event_done: my_write_event