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The record_co2_level_to_sheet rule (lines 16-28), is guarded by a where clause (line 17), so it will not be selected until the pico/ruleset has a value for ent:url. It uses the entity variable instead of the global name (line 22). Otherwise, it is unchanged.
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How does the operator provide the URL value (which includes identifiers that need to be secret)? By sending the co2_recorder:new_url event with the URL as the value of the url event attribute. Notice that the Testing tab is a convenient way to do this, because the (shared) __testing map contains an entry for this event/attribute in line 7.
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