I've built a custom alert action with a UI. One of my inputs is dynamic, and populated from a splunk search. Here is the markup in custom alert HTML file.
I need the ability to enter a custom value as well, but allow-custom-value has no impact. According to this code sample it should work: https://docs.splunk.com/Documentation/Splunk/6.5.2/AdvancedDev/CustomAlertUI#Dynamic_input_controls
<splunk-control-group label="THINGID">
<splunk-search-dropdown name="action.myapp.param.thingid"
search="host=things| sort thingid | table thingid thingnum| dedup thingid"
label-field="thingnum" value-field="thingid"
allow-custom-value/>
</splunk-control-group>
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